Do not indent/unindent if selection end is not at different line
Also, do not indent/unindent the last line of selection if no character is selected in the last selected line
This makes it similar to Visual Studio / Notepad++


git-svn-id: http://tortoisesvn.googlecode.com/svn/trunk/src/TortoiseMerge@24391 4cfb86a4-2c7a-11df-bd14-c1e331e6ceac