todo

# vim:fdm=expr:fdl=1:foldexpr=getline(v\:lnum)=~'^=='?'>1'\:getline(v\:lnum)[0]=~'[*x(]'?'>2'\:getline(v\:lnum)=~'^--'?'<2'\:'='

x support installing packages from git/svn/hg repository
x support for vim::packager  
x installation record
    should record file content checksum too. (for removing plugins)
    if the checksum of a file is mismatched , then we shouldn't unlink the file.
* support pseudo-names: installed , all ... etc 
    vimana list installed
    vimana list all
* support for bzip archive (need a wrapper class)
        Archive::Any sucks.
* force install option
* documentation
* command for upgrading packages
* feature checking
* option for force script type, for example:
    $ vimana install xxxx --type plugin

== issues ==
* should prompt "package can not found." when query a info page of an unknown package.
* package doensn't have a cname if you install from a git uti.