subrepo: fix python2.4 compatibility after
9aa6bee6e9f9
super(SubrepoAbort, self).__init__(*args, **kw) raises
TypeError: super() argument 1 must be type, not classobj
test-keyword: improve grammar and spelling in branchcache note
See:
da9e544c69d6
repoview: extract hideable revision computation in a dedicated function
This will help extensions to plug into the hidden mechanism.