Added search engines

Baidu
DuckDuckGo
Yandex
StartPage
Return UserAgent override support
Add new search engines to Makefile
add alternative asynchronous select helper
mozilla style indentation
disable debug output
Merge pull request #22 from rojkov/jb7533

Alternative asynchronous Select helper that can be used instead of SelectHelper.js
[embedlite] Add alternative async select API. Merge remote-tracking branch 'origin/master'