[NET-216] Make commitString.m shell agnostic (#62)

make sprintf one line

Author: pollaro

+nla/+helpers/+git/commitString.m

@@ -3,8 +3,8 @@
 
     if ~exist('full', 'var'), full = false; end
 
-    cmd_str = sprintf('cd %s\ngit rev-parse %%s HEAD', nla.findRootPath());
-    [cmd_status, branch_name] = system(sprintf(cmd_str, '--abbrev-ref'));
+    cmd_str = sprintf('cd %s\ngit rev-parse --abbrev-ref HEAD', nla.findRootPath());
+    [cmd_status, branch_name] = system(sprintf(cmd_str));
     if cmd_status ~= 0
         str = 'Failed to locate git repository';
         return