Fixed issue #3517 Revision graph filter does not work

I fixed #3517 (closed)

Change in RevisionGraphDlgFunc.cpp looks tricky. So I elaborate intended git command below.

	CurrentBranch is checked	LocalBranches is checked	Both are unchecked
Only <from> is enterd	git log ^<from> HEAD	git log ^<from> --branches	git log ^<from> --all
Only <to> is enterd	git log <to> (Checkbox is ignored)	git log <to> (Checkbox is ignored)	git log <to>
Both are enterd	git log <from>..<to> (Checkbox is ignored)	git log <from>..<to> (Checkbox is ignored)	git log <from>..<to>
Both are empty	git log	git log --branches	git log --all

Change in Git.cpp looks scary because of its big influence. But I believe there's no reason to clear the "range" argument when "--all" or "--branches" is performed. I didn't find any problem during my test.

I'm new to this project. Any suggestions including refactoring are very welcome!

Signed-off-by: Shun Tsukamoto Shun.G.Tsukamoto@gmail.com