hgweb: use lrwxrwxrwx as the permissions of a symlink

Make hg add foo; hg mv foo bar work. - foo will be removed (the user has a copy of its contents in bar) - bar will not be marked as a copy (there was no committed version of foo). We print a warning telling that to the user. Fixes issue269.

test-copy2: use status -C instead of debugstate | grep copy

test-rename: use hg status -C; don't use hg debugstate | grep copy

Make hgk handle filenames with spaces (issue49)

Use "--config ui.report_untrusted=false" for hg calls in hgk, fixes issue523. tcl's exec yields an error if output to stderr happens and isn't redirected to a file, so the warnings about untrusted .hg/hgrc caused problems in hgk. The warning is still printed when executing 'hg view', so the user can see it when using it from the shell.

Added full URL to debug output if something doesn't look like an http hg repo. This way it is easier to debug problems with failing subcommands, like changegroupsubset due to permission problems, when generally accessing the repository works fine.

Handle extensions with defined but empty cmdtable