CBD-979: Revert file_name_utils to C

There seems to be a bug in the mingw compiler causing the build
to fail on windows.

Change-Id: I9e34a34d4e698c8c333ceee1681915f5062fd259
Reviewed-on: http://review.couchbase.org/29380
Reviewed-by: Filipe David Borba Manana <fdmanana@gmail.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>
MB-9310 Pass -lv8 explicitly to LDFLAGS for index builder

This is a blind attempt to fix linker errors on one of the Windows
build bot machines. Wasn't needed on GNU/Linux, Mac OS X nor a
Windows 7 + mingw VM tested on before.

Change-Id: I963d5a16df3ccf05de83ae2819579a1d8a1a32bf