Add plain text make target.

Doc/Makefile

@@ -21,6 +21,7 @@ help:
 	@echo "  web       to make file usable by Sphinx.web"
 	@echo "  htmlhelp  to make HTML files and a HTML help project"
 	@echo "  latex     to make LaTeX files, you can set PAPER=a4 or PAPER=letter"
+	@echo "  text      to make plain text files"
 	@echo "  changes   to make an overview over all changed/added/deprecated items"
 	@echo "  linkcheck to check all external links for integrity"
 	@echo "  coverage  to check documentation coverage for library and C API"
@@ -75,6 +76,10 @@ latex: build
 	@echo "Run \`make all-pdf' or \`make all-ps' in that directory to" \
 	      "run these through (pdf)latex."
 
+text: BUILDER = text
+text: build
+	@echo "Build finished; the text files are in build/text."
+
 changes: BUILDER = changes
 changes: build
 	@echo "The overview file is in build/changes."

Doc/README.txt

@@ -51,6 +51,8 @@ Available make targets are:
  * "latex", which builds LaTeX source files that can be run with "pdflatex"
    to produce PDF documents.
 
+ * "text", which builds a plain text file for each source file.
+
  * "linkcheck", which checks all external references to see whether they are
    broken, redirected or malformed, and outputs this information to stdout
    as well as a plain-text (.txt) file.