hgweb: add revset syntax support to search
This mode is used when all the conditions are met:
- 'reverse(%s)' % query string can be parsed to a revset tree
- this tree has depth more than two, i.e. the query has some part of
revset syntax used
- the repo can be actually matched against this tree, i.e. it has only existent
function/operators and revisions/tags/bookmarks specified are correct
- no revset regexes are used in the query (strings which start with 're:')
- only functions explicitly marked as safe in revset.py are used in the query
Add several new tests for different parsing conditions and exception handling.
$ hg init
$ echo 123 > a
$ hg add a
$ hg commit -m "first" a
$ mkdir sub
$ echo 321 > sub/b
$ hg add sub/b
$ hg commit -m "second" sub/b
$ cat sub/b
321
$ hg co 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ cat sub/b 2>/dev/null || echo "sub/b not present"
sub/b not present
$ test -d sub || echo "sub not present"
sub not present