mercurial.el: fix error on hg-read-rev() with small tip, and cleanups * Fix error if tip revision is smaller than hg-rev-completion-limit If tip revision is 10, "hg log -r -100:tip" fails. * Remove dependencies on cl package at runtime Quote from GNU Emacs Lisp Reference Manual, Emacs Lisp Coding Conventions: > * Please don't require the `cl' package of Common Lisp extensions at > run time. Use of this package is optional, and it is not part of > the standard Emacs namespace. If your package loads `cl' at run > time, that could cause name clashes for users who don't use that > package. * Check XEmacs at compile time Since byte-compiled file is not portable between GNU Emacs and XEmacs, checking type of emacs can be done at compile time. This reduces byte-compiler warnings. * Defvar variables binded dynamically and used across functions * Combine status output string to state symbol alist into a variable, and use char instead of string for key of state alist * Make hg-view-mode as minor-mode * Define keymaps as conventions