[FIX,NOP] fixed travis build errors during contrib build
[NOP] avoid installation of latex during before script to save some build time
[NOP] added searchengines to travis test builds
[NOP] install only required boost libs during travis setup
[NOP] fixed path issue while fetching search engines
Merge pull request #719 from aiche/fix/travis-clone-problems

[CI,FIX] fix travis contrib clone problems