remove related pid file when kill the controlled process among seafile-controller
modify commited code format
fixed typo, purely cosmetic

"executable" was written as "exectuble" and "exectuable"
Merge pull request #721 from SpiritQuaddicted/patch-1

fixed typo, purely cosmetic
change indent of commited code
Remove simplejson import

"import json" works in Python >= 2.6. simplejson is only useful for Python <=
2.5, which seafile doesn't seem to be targeting.
Merge pull request #718 from jyelee/master

remove related pid file when kill the controlled process among seafile-controller
Merge pull request #723 from brutasse/fix/simplejson

Remove simplejson import
Fix daemon mode in multiple programs under OSX

  - seaf-controller
  - seaf-daemon
  - fileserver
  - seaf-server
Merge pull request #726 from Chilledheart/daemonize_under_osx

Fix daemon mode in multiple programs under OSX
[scripts] remove obsolete setupmac.sh
Merge pull request #731 from Chilledheart/remove_setupmac

[scripts] remove obsolete setupmac.sh
[README] use svg icon for travis-ci
Merge pull request #735 from Chilledheart/use_svg_icon

[README] use svg icon for travis-ci
[build] prevent bad sed usage under osx
Merge pull request #737 from Chilledheart/fix_sed_osx

[build] prevent bad sed usage under osx
[server] Add cache support for repo

  - [fix] correct some typos and mistakes mentioned by killing
  - [fix] expire cache in seaf_branch_manager_test_and_update_branch in branch.c
  - [fix] expire cache in set_virtual_repo_base_commit_path in virtual-repo.c
  - [impl] TTL support for cache