Cannot build on Archlinux

[andreasbaumann]

On Archlinux there is a php-config and a php binary for Php 7 (php56 and php-config56 for Php 5.6). On every Linux distribution those binaries are called slightly different, that's why probing has to happen first for the specific versions, then for more generic versions.

Suggested solution for 3rdParty/papuga/php7/php.cmake:

find_program( PHP7_CONFIG_EXECUTABLE NAMES "php-config7.1" "php-config7.0" "php-config7" "php-config" )
find_program( PHP7_EXECUTABLE NAMES  "php7.1" "php7.0" "php7" "php")

PHP php-config executable:  PHP7_CONFIG_EXECUTABLE-NOTFOUND
PHP php executable: PHP7_EXECUTABLE-NOTFOUND
CMake Error at strusBindings/3rdParty/papuga/php7/php.cmake:13 (string):
  string sub-command REPLACE requires at least four arguments.
Call Stack (most recent call first):
  strusBindings/3rdParty/papuga/php7/CMakeLists.txt:6 (include)

CMake Error at strusBindings/3rdParty/papuga/php7/php.cmake:14 (string):
  string sub-command STRIP requires two arguments.
Call Stack (most recent call first):
  strusBindings/3rdParty/papuga/php7/CMakeLists.txt:6 (include)

CMake Error at strusBindings/3rdParty/papuga/php7/php.cmake:15 (string):
  string sub-command REPLACE requires at least four arguments.
Call Stack (most recent call first):
  strusBindings/3rdParty/papuga/php7/CMakeLists.txt:6 (include)

PHP include dirs: 
CMake Error at strusBindings/3rdParty/papuga/php7/php.cmake:20 (string):
  string sub-command REPLACE requires at least four arguments.
Call Stack (most recent call first):
  strusBindings/3rdParty/papuga/php7/CMakeLists.txt:6 (include)

CMake Error at strusBindings/3rdParty/papuga/php7/php.cmake:21 (string):
  string sub-command STRIP requires two arguments.
Call Stack (most recent call first):
  strusBindings/3rdParty/papuga/php7/CMakeLists.txt:6 (include)

PHP library dirs: 
CMake Error at strusBindings/3rdParty/papuga/php7/php.cmake:27 (string):
  string sub-command REPLACE requires at least four arguments.
Call Stack (most recent call first):
  strusBindings/3rdParty/papuga/php7/CMakeLists.txt:6 (include)

CMake Error at strusBindings/3rdParty/papuga/php7/php.cmake:28 (string):
  string sub-command STRIP requires two arguments.
Call Stack (most recent call first):
  strusBindings/3rdParty/papuga/php7/CMakeLists.txt:6 (include)

PHP libraries: 
PHP extension dir: 
PHP .ini file: 
CMake Error at strusBindings/3rdParty/papuga/php7/CMakeLists.txt:21 (include_directories):
  include_directories given empty-string as include directory.

CMake Warning (dev) at strusBindings/3rdParty/papuga/php7/CMakeLists.txt:28 (link_directories):
  This command specifies the relative path

  as a link directory.

  Policy CMP0015 is not set: link_directories() treats paths relative to the
  source dir.  Run "cmake --help-policy CMP0015" for policy details.  Use the
  cmake_policy command to set the policy and suppress this warning.
This warning is for project developers.  Use -Wno-dev to suppress it.

PHP php-config executable:  PHP7_CONFIG_EXECUTABLE-NOTFOUND
PHP php executable: PHP7_EXECUTABLE-NOTFOUND
CMake Error at strusBindings/3rdParty/papuga/php7/php.cmake:13 (string):
  string sub-command REPLACE requires at least four arguments.
Call Stack (most recent call first):
  strusBindings/src/lang/php7/CMakeLists.txt:6 (include)

CMake Error at strusBindings/3rdParty/papuga/php7/php.cmake:14 (string):
  string sub-command STRIP requires two arguments.
Call Stack (most recent call first):
  strusBindings/src/lang/php7/CMakeLists.txt:6 (include)

CMake Error at strusBindings/3rdParty/papuga/php7/php.cmake:15 (string):
  string sub-command REPLACE requires at least four arguments.
Call Stack (most recent call first):
  strusBindings/src/lang/php7/CMakeLists.txt:6 (include)

PHP include dirs: 
CMake Error at strusBindings/3rdParty/papuga/php7/php.cmake:20 (string):
  string sub-command REPLACE requires at least four arguments.
Call Stack (most recent call first):
  strusBindings/src/lang/php7/CMakeLists.txt:6 (include)

CMake Error at strusBindings/3rdParty/papuga/php7/php.cmake:21 (string):
  string sub-command STRIP requires two arguments.
Call Stack (most recent call first):
  strusBindings/src/lang/php7/CMakeLists.txt:6 (include)

PHP library dirs: 
CMake Error at strusBindings/3rdParty/papuga/php7/php.cmake:27 (string):
  string sub-command REPLACE requires at least four arguments.
Call Stack (most recent call first):
  strusBindings/src/lang/php7/CMakeLists.txt:6 (include)

CMake Error at strusBindings/3rdParty/papuga/php7/php.cmake:28 (string):
  string sub-command STRIP requires two arguments.
Call Stack (most recent call first):
  strusBindings/src/lang/php7/CMakeLists.txt:6 (include)

PHP libraries: 
PHP extension dir: 
PHP .ini file: 
CMake Error at strusBindings/src/lang/php7/CMakeLists.txt:79 (install):
  install TARGETS given no LIBRARY DESTINATION for module target
  "strus_bindings_php7".