Map M-* to tags-loop-continue.

SLIME and elisp-slime-nav-mode use M-, for pop-tag-mark. that stomps
on its default binding to tags-loop-continue, which I use all the time
for dired searches across multiple files.

So, I'm swapping the default bindings:
 M-, --> pop-tag-mark
 M-* --> tags-loop-continue
Continue to fix naming conventions.
Use ` as shortcut for home and Dropbox dirs when finding files.

Borrowed from Magnar:
 http://whattheemacsd.com/setup-ido.el-02.html
Continue to fix naming conventions.
Misc ibuffer changes: add group for ERC buffers, enable hl-line-mode.
Dired updates: improved navigation, enable hl-line-mode.

Borrowed from Magnar:
http://whattheemacsd.com/setup-dired.el-02.html
Fix diminish for view-mode in Emacs 24.3.
Turn of smart-tab in shell and nxml modes.
On Mac use Option key as super.
Remove hideshow customization for nxml mode. Prefer to disable this for XML docs.
Use read-only-mode vs. view-mode for read-only buffers like *Messages*/
Try pabbrev mode.
Add my-fold-dwim, misc customizations.

Includes:
- add my-fold-dwim to fold region or current block using Magnar's fold-this package
- add my/kill-and-join-forward
- add my/uniquify-xx commands for region and buffer
- clean up el-get extensions, try a few new ones
Disable tab/hideshow, trying my-fold-dwim instead.