Then, all classes in editor/txmgr is now in mozilla namespace and all
headers which are included by other directory are now exposed. So,
we can remote local includes from other directories now.
MozReview-Commit-ID: Kdb1c4Hp9Sy
--HG--
rename : editor/txmgr/nsTransactionStack.cpp => editor/txmgr/TransactionStack.cpp
rename : editor/txmgr/nsTransactionStack.h => editor/txmgr/TransactionStack.h
extra : rebase_source : 75035e9e618680af9188820595ab050b612a456f