ftp location source does not return correct paths

[Nimdraug]

taters.locations.ftp( 'ftp://a.com/x/y' ).source() yields files with their dirname set to /x/y (as in /x/y/somefile.txt), which when passed to a local location will attempt to create that path, causing a permission error.

Additionally, local locs should not accept absolute paths in the first place, and always assume they are relative to the local loc's basepath. Fixing this would also resolve this issue.

[Nimdraug]

taters.locations.ftp's source now behaves consistently, as does all the other of the locations.

local locs still accept files with absolute paths tho, which will need to be fixed in the future

[Nimdraug]

Locations accepting absolute files split into #2
Closing this as fixed.