#384 Use tilde (~) for player-unique map paths

[Kevin Zheng]

Paths to player-unique maps are represented internally as an absolute
filesystem path to the save map file. Since this path is relative to
LOCALDIR, moving a player file from one server to another could result
in invalid paths. This change replaces full filesystem paths with paths
that begin with (~).

Both the map loading and saving code now internally replace (~) with
LOCALDIR/PLAYERDIR. The map loading code also rewrites the old paths on
load to maintain a consistent path convention.

As a result, we no longer need to explicitly hide local filesystem paths
in the 'who' and 'mapinfo' commands; this change reverts r21263.

[Nicolas Weeger]

Applied as r21609, thanks :)