Merge pull request #26 from heyongjian/master

huangming:merge the main branch to native branch.
Merge pull request #27 from heyongjian/master

huangming:merge the main branch to native branch.
huangming:add the backup and recover function for joy launcher.
Merge pull request #36 from whuthm/master

huangming:add the backup and recover function for joy launcher.
Merge pull request #28 from heyongjian/master

huangming:merge the main branch to native branch.
huangming:unify the PreferencesProvider.java code.
Merge pull request #37 from whuthm/master

huangming:unify the PreferencesProvider.java code.
fix bug issue-2：preferences in hotseat make launcher crash
Merge branch 'master' of https://github.com/heyongjian/joy_launcher
Merge pull request #39 from lwanghaol/master

Merge pull request #18 from heyongjian/master
Merge pull request #19 from heyongjian/master

merger