[common] cleanup avl and related code
[common] remove unused functions

 - seaf_repo_manager_get_repo_prefix
 - seaf_repo_manager_repo_exists_prefix
[client] Fix rename problem on Windows and Mac.

The case is that a file/dir's name changes in cases.
Merge branch 'cleanup_avl' into 3.1
Clean up repo hash table code.
Remove some code with copyright problems.
Remove bitfield code.
[server] List corrupted repos for admin and owner.
[server] Don't return corrupted repos for owner.
update msi/deb version to 3.1.2
[scripts] add seaf-gc wrapper
Update Mac version to 3.1.2.
Don't include "index.h" in server code.
Add seaf-gc.sh to server package.
remove hardcoded "*.tmp" and "*.TMP" from ignore_tables
Merge pull request #764 from Chilledheart/remove_hardcoded_tmp

remove hardcoded "*.tmp" and "*.TMP" from ignore_tables
[client] Fix sync noitification pop-up problem.
[client] Update version to 3.1.3.
Merge branch '3.1'