Avoid extra filelogs entries. Right now, there are some situations in which localrepo.filecommit can create filelog entries even though they're not needed. For example: - permissions for a file have changed; - qrefresh can create a filelog entry identical to its parent (see the added test); - convert-repo creates extra filelog entries in every merge where the first parent has added files (for example, changeset ebebe9577a1a of the kernel repo added extra filelog entries to files in the arch/blackfin directory, even though the merge should only touch the drivers/ata directory). This makes "hg log file" in a converted repo less useful than it could be, since it may mention many merges that don't actually touch that specific file. They all come from the same basic problem: localrepo.commit (through filecommit) creates new filelog entries for all files passed to it (except for some cases during a merge). Patch and test case provided by Benoit. This should fix issue351.

adding a
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
% expect ssl error
pushing to http://localhost:20059/
searching for changes
ssl required
% expect authorization error
pushing to http://localhost:20059/
searching for changes
push not authorized
% expect authorization error: must have authorized user
pushing to http://localhost:20059/
searching for changes
push not authorized
% expect success
pushing to http://localhost:20059/
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
rolling back last transaction
changegroup hook: HG_NODE=ba677d0156c1196c1a699fa53f390dcfc3ce3872 HG_SOURCE=serve HG_URL=remote:http 
% expect authorization error: all users denied
pushing to http://localhost:20059/
searching for changes
push not authorized
% expect authorization error: some users denied, users must be authenticated
pushing to http://localhost:20059/
searching for changes
push not authorized