Build system fixes

[insaneinside]

These are some simple changes meant to enable better use of the build system.

• The first change adds a rule to Makefile.in that will re-run configure (via config.status to ensure the same user-options) if Makefile.in changes -- regenerating the Makefile.
• The second change/commit enables building ChaNGa in a separate directory (e.g. by running "/path/to/changa-source/configure [options]" from that directory). This can be useful for a number of reasons, not the least of which is the ability to have multiple different builds of the project at the same time and without much effort by the user.

I'm not 100% sure I wrote the out-of-source pattern rules in Makefile.in (l. 144-155) correctly, so let me know what needs changing and I'll take care of it.

[trquinn]

I tried this on "stampede" and ran into the following error: ../../charm/bin/charmc -O3 -DINTERLIST_VER=2 -DHEXADECAPOLE -DCOOLING_NONE -DREDUCTION_HELPER -DMERGE_REMOTE_REQUESTS -DCHANGESOFT -g -O2 -I.. -c -o dumpframe.o ../dumpframe.c ../dumpframe.c:11:20: error: config.h: No such file or directory

I think you need to add a "-I$SOURCE_DIR" to the CFLAGS define similar to what you added to the CXXFLAGS define in Makefile.in.

[insaneinside]

You didn't have any problems with the generated Makefile.dep listing "liveViz.h" (i.e. with no path in front of it) as a dependency for any object built from a source that includes ParallelGravity.h? Trying a clean build just now I had to change #include "liveViz.h" to #include <liveViz.h> to avoid that. (Apparently the Charm dependency-generation code doesn't actually do a search for quoted includes or something.)

[insaneinside]

Fixed both of those issues with these two most recent commits, in any case.