Support separate build directories.

The reference to "$(top_srcdir)" was present since commit e186c0a,
but needs to be "$(top_builddir)" in order to support out-of-source
builds.

I'll accept the responsibility for not catching this during review.
Correct a number of lingering white-space issues

This commit adopts the common Automake formatting conventions of
other OPM modules.
Merge pull request #27 from bska/clean-build

Clean build
Merge branch 'release/2013.03'

Conflicts:
	examples/Makefile.am
Quote possibly empty variable to avoid error message

On RedHat 6.4 workstation the module doesn't find the necessary system
information, and gives an error message when the last parameter to the
string function is not present.
Read /etc/system-release if others not parseable
Corrected mismatched if-else-endif arguments
Merge pull request #51 from rolk/051_distrib

Fix bug in reporting of system release (on RHEL 6.4)