301 Valid Delete Options

[kk]

Fixes issue #301. Attempting to delete a branch will now only show valid delete options.

Test case setup:

• Sign in to VisualGit
• Clone/open a repository
• Click the branch dropdown menu

Test case 1:

• Click delete on a local branch (without a remote branch) Expected result:

Test case 2:

• Click delete on a remote branch (without a local branch) Expected result:

Test case 3:

• Click delete on a branch that is remote and local Expected result:

The branch delete function should also be tested by deleting a branch and checking if a the branch is deleted via "git branch -a".

[pqua613]

Based on the above test cases, I can't find any problems with this implementation. I did find that 2 remote branches can't be deleted in the same session. This, however, is outside the scope of this issue and another issue should be created to address this.