Support more evil-cleverparens commands

[bmag]

This is the second and final batch of evil-cleverparens. I believe I covered all of evil-cp's commands, if I have left any it shouldn't be hard to add them. There are still four commands that don't integrate with evil-mc, see details below.

These commands work, but don't appear in the code because they didn't require any handlers:

• evil-cp-backward-up-sexp
• evil-cp-up-sexp
• evil-cp-backward-symbol-begin
• evil-cp-forward-symbol-end
• evil-cp-backward-sexp
• evil-cp-forward-sexp
• evil-cp-forward-symbol-begin
• evil-cp-previous-opening
• evil-cp-next-closing
• evil-cp-next-opening
• evil-cp-previous-closing
• evil-cp-beginning-of-defun
• evil-cp-end-of-defun
• evil-cp-backward-symbol-end
• evil-cp-toggle-balanced-yank
• evil-cp-yank-sexp
• evil-cp-yank-enclosing

These commands are not supported:

• evil-cp-delete-backward-word: I added the same handler that evil-delete-backward-word has, but it doesn't seem to work.
• evil-cp-change-whole-line: evil-change-whole-line doesn't have a handler either
• evil-cp-yank-line: evil-yank-line doesn't have a handler either
• evil-cp-override: didn't figure how to make a proper handler for this one, see detailed comment in the code.

A technical git-related note: I rebased the changes from master before adding the new commit. Git didn't show any errors, so it's probably fine, but you may want to double-check that merging this PR won't erase existing code.

[gabesoft]

Great work. I may start using evil-cleverparens as well.