gnucash master: More fiddling with gtest linkage.

[John Ralls]

Updated	 via  https://github.com/Gnucash/gnucash/commit/290dd611 (commit)
	from  https://github.com/Gnucash/gnucash/commit/b78f1029 (commit)



commit 290dd611d71395e01ced722f1306ccbec8c00457
Author: John Ralls <jralls at ceridwen.us>
Date:   Thu Jul 23 17:47:23 2015 -0700

    More fiddling with gtest linkage.
    
    This time for when we don't have a system installation.



Summary of changes:
 configure.ac            |  17 ++-
 macros/m4_ax_pthread.m4 | 332 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 347 insertions(+), 2 deletions(-)
 create mode 100644 macros/m4_ax_pthread.m4