tests/test-1102.t

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.

  $ rm -rf a
  $ hg init a
  $ cd a
  $ echo a > a
  $ hg ci -Am0
  adding a
  $ hg tag t1 # 1
  $ hg tag --remove t1 # 2

  $ hg co 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg tag -f -r0 t1
  $ hg tags
  tip                                3:a49829c4fc11
  t1                                 0:f7b1eb17ad24

  $ cd ..