[PC-BSD Testing] Inconsistence: meta-packages install name does not match the filename

[Live user]

For example, the package XBMC, to be installed requires

# pc-metapkgmanager add XBMC

While in mirror the packages is named xbmc-11.0_6.txz

Wouldn't be a better idea to allow meta-pkgmanager install via

# pc-metapkgmanager add xbmc