[Improvement] Rename request parameters to make them accessibly by JSP expressions

Rename the infos/warnings/errors request parameters like this:

- webl:infos --> weblinfos
- webl:warnings --> weblwarnings
- webl:errors --> weblwarnings

This makes them accessible in JSP expressions like ${weblinfos}.

+API
Merge pull request #342 from myniva/pr/rename-error-request-params

[Improvement] Rename request parameters to make them accessibly by JSP expressions