testlib: move the prune alias into a shell script for Windows
Cramming all of this directly into an alias doesn't play nicely on Windows.
Various test-exchange-obsmarkers-case-XX.t were failing with:
abort: cannot select revision when creating marker
It turned out that inside debugcommands.debugobsolete(), the following differed
from Linux (where they were empty, at least in the case I debugged):
'rev': ['.`;'],
'template': "'{node}\\n'"
#require unix-permissions no-root
$ hg init a
$ cd a
$ echo foo > b
$ hg add b
$ hg ci -m "b"
$ chmod -w .hg/store
$ cd ..
$ hg clone a b
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ chmod +w a/.hg/store # let test clean up
$ cd b
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions
$ cd ..