Enable out-of-source (shadow) builds.

[boppybibbles]

Enable out-of-source (shadow) builds.

Out-of-source build is a widely used practice. Unfortunately it is not possible to use it out of the box because of compiler error.

How to reproduce:

• clone to QtPass directory: git clone git@github.com:IJHack/QtPass.git;
• create build directory which is out of source directory: mkdir build && cd build;
• configure project: qmake ../QtPass;
• make project: make;
• observe compiler error below.

Compiler error:

make[1]: *** No rule to make target '../../QtPass/localization/localization_nl_NL.qm', needed by 'qrc_resources.cpp'.  Stop.
make[1]: Leaving directory '/tmp/build/src'
make: *** [Makefile:49: sub-src-make_first] Error 2

Related to #467.

[issue-label-bot[bot]]

Issue-Label Bot is automatically applying the label feature_request to this issue, with a confidence of 0.81. Please mark this comment with :thumbsup: or :thumbsdown: to give our bot feedback!

Links: app homepage, dashboard and code for this bot.

[boppybibbles]

I am willing to work on it.