LESS_TERMCAP_xx vars; pretty man pages. /via @richo
Unset LESS_TERMCAP_{so,se} as they're breaking search highlighting.

* The color made the search terms hard to find on the screen.
* The reset code nuked formatting for the remainder of the line.
    * e.g. green diff line would be reset to white after the highlight.
Remove Ruby 1.9.3 "optimizations" from ENV; ruby 2.1 hates them.

Warning emitted by Ruby 2.1.0p0:

    ~/.rubies/ruby-2.1.0/bin/ruby: warning: RUBY_HEAP_MIN_SLOTS is obsolete. Use RUBY_GC_HEAP_INIT_SLOTS instead.