fix chinese
It seems that we should unescape task name returned in json
prevent re-downloading when downloaded file size is smaller than expected.
refactor download tool so I can add aria2c download completion check later
check .aria2 file
if hash fails, don't delete file. instead, rename it to *.error
move download file to top level, so can you hack it easily.
remove download_tool from function arguments
remove expired tasks correctly when paging
fix paging when task number > 100
It seems that we should unescape the original URL returned in json too...
fix paging when the page number > 8
fix bt task
fix #267, paging error for empty task list
fix #268: lx export-download-urls
add --all options to `lx export-aria2` and `lx download-aria2`
check args before login
Merge branch 'master' of git://github.com/iambus/xunlei-lixian into iambus-master

Conflicts:
	lixian_commands/download.py