Most user actions now go through vebugger#userAction, which calls the
user action on the active debugger object. The exceptions are:
- Starting the debugger - because we don't have an active debugger yet
- Stopping the debugger - because we'll need to clear the active
debugger after that
- Altering breakpoints - because we want to be able to do it even
without an active debugger(e.g. - setting breakpoints before starting
the debugger)
Only supports setting variables and executing functions, because that's
what GDB supports(via different commands)(I think - didn't find anything
else...)
Now:
- `e` and `w` eval and write the word(`e`) or line(`w`) under the
cursor.
- Unless some text is selected - in that case they use the selected
text.
- `E` and `W` prompt the user to type what to eval or write.
Didn't add command for starting JDB, since it's too complex to provide
the source and classes file path in a command - might as well leave it
as a Vim function...
