The gitdir global variable is essentially read-only, and is used rather
frequently. So are appname and reponame. Needing to constantly declare
'global appname' just so we can access the value as $appname is downright
annoying and redundant. So instead I'm declaring these as procedures and
changing all uses to invoke the procedure rather than access the global
directly.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>