Update search challenges api

1. Remove screenScorecardId and reviewScorecardId

2. Update api doc
Fix type error in get challenge api.
Merge pull request #352 from Ghost141/get_challenge_api_fix

Fix type error in get challenge api.
Merge pull request #351 from Ghost141/challenges_api_update

Update search challenges api
filter 'fileData' in log.
Merge branch 'technology-2014-09-18' into dev
Merge branch 'technology-2014-09-18' into dev
Fix typo in submit for develop challenge api.
Merge pull request #355 from Ghost141/submit_api_update

Fix typo in submit for develop challenge api.
Merge branch 'technology-2014-09-25'