Add the constant to cache 'Components.utils' to modules/base.js.
Merge pull request #439 from saneyuki/fix

Add the constant to cache 'Components.utils' to modules/base.js.
Refer "prefs" instead of "window['...'].prefs" to load depending modules
Change TreeStyleTabBase.SessionStore simply.
Merge pull request #441 from saneyuki/ss

Change TreeStyleTabBase.SessionStore simply
Move TreeStyleTabBase.migratePrefs() to TreeStyleTabUtils .migratePrefs().
Merge pull request #442 from saneyuki/migrate

Move TreeStyleTabBase.migratePrefs() to TreeStyleTabUtils.migratePrefs()
Fix typo
TreeStyleTabBase should not inherit "prefs"
Split definitions of constant properties from TreeStyleTabBase
TreeStyleTabBase should not inherit "prefs" (part 2)
Freeze TreeStyleTabConstants.
We treat this as constants.
Merge pull request #443 from saneyuki/constant

Freeze TreeStyleTabConstants.
Remove setting TreeStyleTabUtils.__proto__.
Merge pull request #444 from saneyuki/constant2

Remove the setting TreeStyleTabUtils.__proto__.
Fix missing "TreeStyleTabUtils" symbol for modified functions
Rename conflicting variable:
prefs =>
subTreePrefs
Rename conflicting variable:
prefs =>
subTreePrefs
Merge branch 'master' of github.com:piroor/treestyletab

Conflicts:
	modules/utils.js
Don't set margin to indicate grouped tabs for parent tabs next to hidden tabs (#463)