[v2] modified repo create, file upload, update, download, ...

* repo create: myhome, pubrepo, group
* handled 'is_password_set' etc.
* view-online is not offered for file in enc repo in 'passwd local' mode
* removed 'open local file'
* added 'v2 tip' in seafile_access_check page
[v2] improvements ('random_key' --> 'file_key', and etc)

* 'KEEP_ENC_REPO_PASSWD' --> 'SERVER_CRYPTO'
* random_key --> file_key. added client_crypto.js
* file upload/update: don't encrypt when file size is 0
* combine 'sjcl.min.js' and 'codecBytes.js' into 'sjcl.js'
* added 'repo_create_js_fils.html', 'included' it