cat: return an error on failure

tests: add merge test for changeset 9fe267f77f56 When all the files in a directory are moved somewhere else, and new files are added in changesets of the local branch, a subsequent pull and merge shouldn't rename the locally added files too.

purge: add the clean alias inspired by git-clean and svn-clean

mercurial.el: ignore errors on hg-after-save-hook() Don't signal an error even if running hg command fails. Otherwise, succeeding hooks won't be called.

mercurial.el: change default log range to tip:0 If the tip revision is smaller than hg-rev-completion-limit (defaults to 100), "hg log -r tip:-100" fails. Since performance does not differ between "hg log -l 50 -r tip:0" and "hg log -l 50 -r tip:-100" even on large repository, default range can be changed from "tip:-100" to "tip:0" without any drawbacks.

Command in doc comment is now on a single line, fixed after previous formatting broke it.

purge: don't delete ignored files if --all is not specified

Enable to select encoding in hgrc web section This patch provides character encoding setting in each repository. After this patch, You can use multi encoding repositories with one mercurial server.