Improve PrettyPrinter construction perf by not using uniqid

The uniqid function is *very* slow on unix systems. The code has no
particular unique-ness requirements, so the much faster mt_rand()
function is used instead.

Closes PR #65.
Fix pretty printing of `include` expressions
Fix notices when generating expected tokens list
Fix notices when generating expected tokens list (continued)

Forgot to add regenerated parser
Remove obsolete item from grammar/README.md
Add PHP 5.5 to .travis.yml
Release PHP-Parser 0.9.4
Require ext/tokenizer in composer.json
Add NodeTraverser::removeVisitor()
Fix name resolver (class names are case insensitive)
s/Elseif/ElseIf/
Merge pull request #81 from brikou/Elseif_to_ElseIf

Rename "Elseif" to "ElseIf"
Updated travis.yml
Merge pull request #86 from GrahamCampbell/travis-tweaks

Run travis tests on hhvm as well
Ensure no registered error handler will see the 'reset' error
Synchronized error messages with native php error messages
added doc in AST (and also in php-analysis repo)
Merge remote-tracking branch 'upstream/0.9' into v0.9
added .idea to git ignore
renamed doc to phpdoc, and boolean values to lowercase