tests: delete parallel coverage files after combining

heads: show closed heads only when --closed is passed Add a --closed (-c) option to 'hg heads' to show all heads and change the default behavior to refrain from showing fully closed branches. Enhance 'hg heads <branch>' so that: * default: displays normal & inactive heads, not closed heads * --closed: displays normal, inactive & closed heads * --active: displays only normal heads * both --closed and --active: displays normal & closed heads only

localrepo: set heads and branchheads to be closed=False by default The heads(...) and branchheads(...) functions will now only return closed heads when explicitly asked for them. This will cause 'hg merge' to have better behavior in the presence of a branch that has closed heads when no explicit rev is passed.

convert: rewrite tags when converting from hg to hg

convert: default revisions order depends on source When converting Mercurial repositories you expect the revision numbers to be preserved, while other sources conversions focus on efficiency.

convert: fail fast if source does not support --sourcesort

convert: add --sourcesort option for source specific sort Only supported by Mercurial source for now.

convert: parse sort mode sooner

convert: split toposort() into subfunctions for readability

run-tests: don't replace PYTHONPATH, just augment it. (Needed at least for Subversion bindings on OS X, which are in /opt/subversion. Useful for other external libraries installed in non-standard places too.)