Implement statusbar UI and indentation controls

[jasonsanjose]

Requires focused editor fixes (issue #1257, pull #1765) to work properly.

[GarthDB]

Couple of changes:

• Added title properties to the labels for tooltips explaining the toggle for spaces and tabs
• On hover the spaces/tabs label should underline, but not the width number.

http://garthdb.github.com/Brackets-UI-Prototypes/status_bar/

[GarthDB]

Also, the currently implementation is slightly tighter than prototype, I would space it out a bit.

[jasonsanjose]

Updated with tooltips, margins and hover changes.

[GarthDB]

looks good.

Couple more recommendations, sorry I didn't include them before

1. In an attempt to make the arrows more clickable I added a pixel of padding on each side.
2. The border top is a little dark on the status bar. The prototype uses border-top: 1px solid #E6E6E6;

[redmunds]

It bugs me that all of the info in the status bar is flowed into a line of text because every time and data changes, all info to the right (or left depending on which side) of whatever changed shifts a few pixels left or right. I would like to see the text layout using fixed width blocks so nothing ever ever shifts.

We could also try using Source Code Pro (monospace) font, but we'd have to pad leading spaces (i.e. so "1", "10", "100" all use same horizontal space).

[jasonsanjose]

Filed #1772

[redmunds]

Done with UI review. Still need to look at code.

[jasonsanjose]

@GarthDB Changed border-top to darken @ step-size/2 percent. Added padding.

[jasonsanjose]

Pushed fixes from initial UI review.

[redmunds]

Looks good. Merging.