run-tests: move t test parsing into its own function
Test parsing is somewhat complicated. This patch extracts it into its
own function.
The impetus of this patch is folding tsttest() into the TTest class.
Subsequent patches will continue this work until tsttest() no longer
exists.
http://mercurial.selenic.com/bts/issue1438
$ "$TESTDIR/hghave" symlink || exit 80
$ hg init
$ ln -s foo link
$ hg add link
$ hg ci -mbad link
$ hg rm link
$ hg ci -mok
$ hg diff -g -r 0:1 > bad.patch
$ hg up 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg import --no-commit bad.patch
applying bad.patch
$ hg status
R link
? bad.patch