Allow shared and static make targets.
Trigger library rebuild if headers changed.
Add longlong.h header to HEADERS.
Move Makefile.mod to Makefile.subdirs because of implicit .mod rule.
Add verbose make target.
Replace Makefile.mod by Makefile.subdirs within Makefile.in.
Fix for make check in subdirs.
Fix for make profile in subdirs.
Add EXEEXT variable for executable extension.
Merge branch 'trunk' into build_system
Fix -lpthread typo.
Fix EXEEXT typo.
Define tests make target to build tests file without running them.