or "ninja -t clean -r <rule>"
Also, modify Cleaner::CleanAll to use Edge::is_phony.
Introduce a rule attribute "generator" which, if present, specifies that this rule is used to re-invoke the generator program. Files built using generator rules are treated specially in two ways: firstly, they will not be rebuilt if the command line changes; and secondly, they are not cleaned by default. A command line flag "-g" is introduced for the clean tool, which causes it to remove generator files. Fixes issue #102.
Clean all was not returning non-zero when an error occur (like when failing to remove a directory). This patch fix the problem and add a test for it.
It also fix a bug about the count of removed file reported.