Improve run-ci's change detection

Ensure that the prefix matches the directory. Using the
entire string results in things like 'php' being run when only
'cakephp' was modified

toolset/run-ci.py

@@ -82,14 +82,14 @@ def _should_run(self):
    '''

    # Look for changes to core TFB framework code
    find_tool_changes = "git diff --name-only %s | grep toolset | wc -l" % self.commit_range
    find_tool_changes = "git diff --name-only %s | grep '^toolset' | wc -l" % self.commit_range
    changes = subprocess.check_output(find_tool_changes, shell=True)  
    if int(changes) != 0:
      log.info("Found changes to core framework code")
      return True
  
    # Look for changes relevant to this test
    find_test_changes = "git diff --name-only %s | grep %s | wc -l" % (self.commit_range, self.test.directory)
    find_test_changes = "git diff --name-only %s | grep '^%s' | wc -l" % (self.commit_range, self.test.directory)
    changes = subprocess.check_output(find_test_changes, shell=True)
    if int(changes) == 0:
      log.info("No changes found for %s", self.name)