#61 Reinstall using `make install` recompiles the package

[Arnel A. Borja]

When gwaei is already installed (an older version, etc.), running make install again will recompile the whole package. This is because system directories are checked for headers before the ones included in the package. When make install is run, it will first update the headers already installed, which makes the timestamp of the headers to be newer than the targets, trigerring recompilation.

I use make install -d to check which triggered recompilation, and they are the newer headers of gWaei installed by the package.

I attached a patch to fix this, by adding the paths in the package before anything else in CFLAGS.