1. for version like 5.05rc major version list will take in as it is
2. for version like 5.00, previously it will return wrong string with negative value in the string, now it is fixed
1. add timing info attribute for activityLogEntry
2. for older logs, no timing info will be shown
3. for new logs, timing info will be shown in format:   m:s:ms
4.only successful request will be timed now
1.add version filter in query
preserve line break in feedback session instructions
1.add joinUrl showing for developing purpose
2.fix related test
1. test whole join link shown in adminHomePage status
2. add comments for hidden instructor join link inside instructorCourseEditPageUitest and the asp file
Merge remote-tracking branch 'origin/master' into 74582646

Conflicts:
	src/test/java/teammates/test/cases/ui/browsertests/InstructorCourseEditPageUiTest.java
	src/test/resources/pages/instructorCourseEdit.html
fix instrcutorCourseEditPageUiTest
1. add text colour for differentiation purpose
2. simplify time format
1. change processTime to timeTaken
2. add parameter to getColorCode function for easy testing
1. extract new instructor account joinUrl getting logic into a deprecated method
improve readability
add comment for version processing in adminActivityLogPageData.java
change comment into explicit variable
1. remove unnecessary methods
2. add <pre> tag to preserve link break
Merge branch 'master' into Issue2220
[2220] adminActivityLog: crashes if the version number includes a non-number

fixes #2220
Merge branch 'master' into 74582646
[Fixes #74582646] show join link for admin and instructor adding for testing purpose
Merge branch 'master' into Issue1369