Rename library and use proper versioning

Previously the version of libproc always tracked the version of procps.
This doesn't work when other non-procps programs link to the library as
they are always playing catch up.

This change makes the library version independent of the procps version.
It will only be incremented when needed.

.gitignore

@@ -28,8 +28,8 @@ pkill
 pmap
 procps-ng-*.tar.gz
 proc/.depend
-proc/libproc-ng.la
-proc/libproc-ng.pc
+proc/libprocfs.la
+proc/libprocfs.pc
 proc/Makefile
 proc/Makefile.in
 ps/Makefile