Move quick reference DOC/PDF files to separate directory

Signed-off-by: Alexander Kriegisch <Alexander@Kriegisch.name>

docs/index.adoc

 |===
 |+++Section+++ |+++Contents+++
 
-|xref:#documentation[Documentation] |xref:faq/faq.adoc#faq[FAQ], xref:dist/doc/quick5.pdf[Quick
-Reference (AspectJ 5)], xref:dist/doc/quick.pdf[Quick Reference (1.2.1)],
+|xref:#documentation[Documentation] |xref:faq/faq.adoc#faq[FAQ], xref:quickref/quick5.pdf[Quick
+Reference (AspectJ 5)], xref:quickref/quick.pdf[Quick Reference (1.2.1)],
 xref:adk15notebook/index.adoc[AspectJ 5 Developer's Notebook],
 xref:progguide/index.adoc[programming],
 xref:devguide/index.adoc[development] and
 [width="100%",cols="50%,50%",options="header",]
 |===
 |Documentation |Description
-|xref:dist/doc/quick5.pdf[AspectJ 5 Quick Reference] |This is a four-page quick
+|xref:quickref/quick5.pdf[AspectJ 5 Quick Reference] |This is a four-page quick
 reference for the AspectJ 5 language.
 
-|xref:dist/doc/quick.pdf[AspectJ Quick Reference] |This is a two-page quick
+|xref:quickref/quick.pdf[AspectJ Quick Reference] |This is a two-page quick
 reference for the AspectJ language.
 
 |xref:adk15notebook/index.adoc[AspectJ 5 Developer's Notebook] +

docs/readme-docs-module.adoc

   AspectJ API's, script snippets, and instructional trails, all intended
   to serve as sources for documentation. See xref:sandbox/readme-sandbox.adoc[].
 * `teaching`: Teaching materials, esp. for the AspectJ tutorials.
-* `quick.doc`: The Microsoft Word source file for the .pdf Quick Reference
-  guides `dist/doc/quick.pdf` and `dist/doc/quickA4.pdf`.
+* `quickref/quick.doc`: The Microsoft Word source file for the .pdf Quick Reference
+  guides `quickref/quick.pdf` and `quickref/quickA4.pdf`.
 * `build.xml`: Ant build script for the doc distribution
 * `developer`: Docs for AspectJ developers
 
 * When building docbook, uses `../lib/saxon` libraries.
 * When building installer, using `../lib/build/build.jar` and the
   `../build/installer-resources`.
-* `dist/doc/quick.pdf` is generated manually from `quick.doc`.
+* `quickref/quick.pdf` is generated manually from `quickref/quick.doc`.
 * `../org.aspectj.lib` provides library sources for
   `{AspectJ}/doc/aspectjlib`.