Allow manual configuration of branches in automatic merging

I'd like the ability to set a "manual" mode for automatic branch merging in Stash. The semantic versioning scheme doesn't always make sense. Perhaps I have a lot of ad-hoc branch names modeled around our own internal process and we do not use the semantic versioning approach.

I still would like the ability to utilize Stash to maintain parity between the branches with transparent and continuous merges. Right now I'm forced to do so by hand on a less-than-ideal frequency because my branch names do not correlate to version numbers.

My proposal:

Add a checkbox or mode called "Manual" or something along those lines. When enabled, two panes activate and become visible. Left side is a list of "Branches to automatically merge" and the right side is "Available branches". From the right side, I should be able to drag & drop branches onto the left panel. The left panel will also allow me to drag & drop items to reorder them from within itself.

Think of how the Issue Schemes work in JIRA. When you configure a scheme, you can drag & drop issues left & right and reorder them. This exact same widget / style should be used here too.

Order of the branches in the left panel determines the merge direction. From top to bottom, the merges will take place. So let's say I have the following branches in the left panel (ordered as shown):

• develop-hardware1
• develop
• develop-hardware2

Merges will occur in the following order:

`develop-hardware1 --> develop --> develop-hardware2`

I should be able to click SAVE or CONFIRM at this point to save the configuration which will make automatic merging effective immediately.