Only compute Git status flags once

Previously the status was fetched twice, once for
if modified and once for if new.

Now the flags are fetched once and Git now provides
helpers to check the status flags directly for
modified and new status.

src/app/git.coffee

@@ -36,19 +36,25 @@ class Git
   isPathIgnored: (path) ->
     @repo.isIgnored(@relativize(path))
 
-  isPathModified: (path) ->
+  isStatusModified: (status) ->
     modifiedFlags = @statusFlags.working_dir_modified |
                     @statusFlags.working_dir_delete |
                     @statusFlags.working_dir_typechange |
                     @statusFlags.index_modified |
                     @statusFlags.index_deleted |
                     @statusFlags.index_typechange
-    (@getPathStatus(path) & modifiedFlags) > 0
+    (status & modifiedFlags) > 0
 
-  isPathNew: (path) ->
+  isPathModified: (path) ->
+    @isStatusModified(@getPathStatus(path))
+
+  isStatusNew: (status) ->
     newFlags = @statusFlags.working_dir_new |
                @statusFlags.index_new
-    (@getPathStatus(path) & newFlags) > 0
+    (status & newFlags) > 0
+
+  isPathNew: (path) ->
+    @isStatusNew(@getPathStatus(path))
 
   relativize: (path) ->
     workingDirectory = @getWorkingDirectory()