fix #172: lx delete --all
fix simplecd
Support short command aliases for download (d), list (l), add (a), and delete (x).
For #107: lx download --no-bt-dir
fix #182: lx add --bt error
fix lx download magnet
lx download --save-torrent-file
fix batch download
print total bt size
lixian_tasks_extended.py -> lixian_extend_links.py
lixian_cli_extended.py -> lixian_commands.py
API to list tasks by category
make sure task type is in lower case
fix #158 and #194: support listing and downloading by category
fix #199: python 2.6 compatibility issue -- dict comprehension was introduced in 2.7
Bug fix: when the network is unavailable, gethostbyname will fail without retry
fix search tasks by date
remove line breaks from base64
Remove duplicate code
refactor lixian_tasks to lixian_query