Hotkeys in dialogs. Step 1. Drawing

The goal of this intermediate commit is to prevent extensive splitting of the codebase. The extensive splitting  might require manual merging. Nothing appears to be broken with the changes.

- Most of text-based dialog components now recognize '&' as a prefix for hotkey character. The components are radio, check, and action butons.
- StaticText is not yet converted to use hotkeys in drawing. The component is utilized do show elements that are not intended for hotkeys. This includes its usage in multi-line text, and in showing filenames. TBD.
- Only drawing hotkey functionality is implemented now. Reacting to the hotkeys will be in the next phase. TBD.
- Options->Styles dialog is &-marked with hotkeys. Also, all OK/Cancel/Yes/No buttons now show hotkey in yellow color.
- Note that wcm dialogs use light gray background, unline Far that uses Cyan color for that - same as menu. Yellow hotkeys look good on Cyan, and not that good on the light gray. Can we change background  in 'Settings' dialogs to Cyan - to match Far color scheme?
Merge pull request #119 from helgp/master

Hotkeys in dialogs. Step 1. Drawing