remove tabs
fix auto-completion if symbol has no namespace

If the symbol returned by idetools has no namespace part, the complete
symbol has been recognized as namespace. Now we split the symbol at
the last dot into namespace and name part, the namespace part possibly
being empty.
set `comment-start` and `comment-start-skip` when mode is started

Set the buffer local variables `comment-start` and
`comment-start-skip` when the mode is enabled. This allows to use
`comment-dwim` directly without the necessity of
`nimrod-comment-dwim`. That is the typical way other modes handle
comment syntax.
copy basic indentation code from python.el

--HG--
extra : amend_source : c2fb65e0e2f03438e3b113db34785ec0d63e17ff
fix regexp for variables

The old regexp did not match single letter variables.
remove unused regular expressions
implement electric colol
initialize keymap as global variable

The original implementation modified the keymap each time nimrod-mode
is enabled in some buffer. However, this might overwrite custom user
bindings.
use `nimrod-rx` for all regexp incuding font-lock
make font-lock case insensitive
bind shift left/right functions
indent continuation lines