bundle branchmap considers heads differently than mercurial does

[glandium]

STR:

• hg clone https://bitbucket.org/pidgin/purple-plugin-pack
• hg -R purple-plugin-pack bundle -a bundle.hg
• git init purple-plugin-pack.git
• git -C purple-plugin-pack.git ls-remote hg::$PWD/bundle.hg

This displays the following refs:

0000000000000000000000000000000000000000	refs/heads/branches/org.guifications.plugins/b09244a51e72cb87c6d395c3f24e161407f83c13
0000000000000000000000000000000000000000	refs/heads/branches/org.guifications.plugins/bf5aa8cf544d15a2dbc24fbe5fbebcd082c38c29
0000000000000000000000000000000000000000	refs/heads/branches/org.guifications.plugins/ecd92b3cbfd45ed3fb0f70f2a4a3a26bf571dc16
0000000000000000000000000000000000000000	refs/heads/branches/org.guifications.plugins/fe247aa14dd6b0aa38cedb3b47167c57d3ab7286

that mercurial doesn't consider as heads. They do have a weird history, where their children belongs to another branch, and the org.guifications.plugins branch re-branches off the children.

[glandium]

This also affects fsck.