Blender Git Loki

Info Editor keymap and UI improvements

This is my first steps with GSoC, excuse any mistakes.

The goal of this change is to make it consistent with outliner.

Keymap changes (change info editor keymap to match outliner):

- click on empty space - deselect
- ctrl + click to select multiple reports
- add active report - last selected
- shift select to select range from active report
- ctrl shift select to select multiple ranges

UI changes:
- indicate active report in info editor
- use the same color scheme as outliner
- do not show zebra in selected reports (be consistent with outliner)
- add new info_active (report) and row_alternate theme setting

Differential Revision: https://developer.blender.org/D7950