2.7.1: Make list of ignored syntax groups configurable

@xolox xolox tagged this Oct 29, 2011 · 121 commits to master since this tag

While trying to fix issue #20 I decided to refactor the code that
handles ignored syntax groups: Previously the list of excluded groups
was hard coded in two places, now it's a configuration option. Then
it turned out that including shFunction* in the list of excluded
syntax groups didn't fix the reported issue...