Check for grepstdchdrs script before calling it.

It is possible that CHPL_DEVELOPER is defined in a release tarball environment,
which does not have util/devel/grepstdchdrs script.
Move the standard C header check to smokeTest.

Previously this check was a compiler make target. Now that smoke test exists it
is more appropriately placed there.

Suggested by @bradcray.

Conflicts:
	compiler/Makefile
Update BUILD_VERSION target to always build.

This behavior was implicit when BUILD_VERSION depended on CheckStandardCHeaders
target. Now that target is gone, the FORCE target is added as a dependency to
ensure BUILD_VERSION is always created/updated.
Merge branch 'master' of github.com:chapel-lang/chapel into fix-check-for-c-std-headers
Fix whitespace.
Add blank line below printchplenv in smokeTest.
Merge branch 'master' of github.com:chapel-lang/chapel into fix-check-for-c-std-headers
Merge pull request #551 from thomasvandoren/fix-check-for-c-std-headers

Move standard C header check to smoke test.

Previously this check was a compiler make target. Now that smoke test exists it
is more appropriately placed there.

Suggested by @bradcray.