escape leading asterisk and leading question mark in spell_check query; unescape leading escaped asterisk and leading escaped question mark in spell_check search
Merge branch '2-0-stable' of github.com:taktsoft/sunspot into 2-0-stable

Conflicts:
	sunspot/lib/sunspot/query/spell_check.rb
	sunspot/lib/sunspot/search/spell_check.rb

Fixed Sunspot::DismaxEscaper: it escaped twice
DismaxEscaper#unescape_term: uses precompiled regexps too