* lisp/doc-view.el (doc-view-pdfdraw-program): Allow "pdfdraw" name.

* lisp/doc-view.el (doc-view-pdfdraw-program): Allow "pdfdraw" name.
(doc-view-pdf->png-converter-function): Use mupdf if available.
(doc-view-djvu->png-converter-function)
(doc-view-ps->png-converter-function): Remove.
(doc-view--image-file-pattern): Replace doc-view--image-file-extension.
(doc-view-goto-page, doc-view-convert-current-doc, doc-view-display)
(doc-view-already-converted-p): Adjust accordingly.
(doc-view-mode-p): Simplify.
(doc-view-enlarge): Use setq-local.
(doc-view-pdf->png-converter-ghostscript)
(doc-view-djvu->png-converter-ddjvu)
(doc-view-pdf->png-converter-mupdf): Rework to call
doc-view-start-process directly.
(doc-view-pdf/ps->png): Simplify accordingly.
(doc-view-pdf->png-1, doc-view-djvu->png-1): Remove.
(doc-view-document->bitmap): Rename from doc-view-document->png.
(doc-view-convert-current-doc): Merge pdf and djvu cases.
(doc-view-set-slice-from-bounding-box): Fix completion table.
(doc-view-mode): Use add-hook for after-revert-hook.