Merge pull request #52 from shlomif/master

README.md: correct a typo and get rid of trailing space.
add -x parameter for aria2c to speed up downloading

manpage:
> -x, --max-connection-per-server=<NUM>
>              The maximum number of connections to one server for each download.  Default: 1

increase the number can briefly help speed up the progress.
Merge pull request #61 from PeterDaveHello/patch-1

add -x parameter for aria2c to speed up downloading
Update ppa info, refer to #58
Merge pull request #62 from PeterDaveHello/patch-1

Update ppa info, refer to #58