Add mc/mark-all-dwim
Add basic tests for 'mc/mark-all-dwim'
Add 'mark-all-dwim' tests for selection
Make 'mc/mark-all-dwim' into 'mc/edit-lines' if prefix arg is passed
Test edit-lines functionality in 'mc/mark-all-dwim'
Refactor mark-dwim tests to share a common background
Add 'mc/mark-all-dwim' to README
Fall straight through in 'mc/mark-all-dwim' if multiple cursors are already active, as that means we can't sensibly edit lines or mark all in region
Mention only 'mc/mark-all-dwim' in README to prevent confusing redundancy
Derp, multiple cursors means > 1, not > 0.
Merge pull request #104 from mathrick/mark-all-dwim

Add new command, mark-all-dwim