DexEdit improvements

[tdewolff]

Needs refactoring and efficiency, it can be slow. Needs a lot of testing!

Firefox:

• can't delete HR (on it's own?)
• keyboard text selection doesn't work
• selection sometimes gets wrong, needs thorough testing

Safari:

• deleteing HR removes a line too many
• selecting sometimes doesn't work, it selects text way before in the paragraph

IE: ?

[tdewolff]

DexEdit is rewritten. Most problems are fixed, except:

• text selection by keyboard (in FF?)

[tdewolff]

All fixed