dist: give 2.0 manual unique DOC_MODULE name

The experimental 2.0 reference manual was setup with  DOC_MODULE name of
"cogl" which conflicted with the 1.x API manual. This meant that when
running make install for both the reference manuals all the html files
would end up bundled together in the same location. The 2.0 API
reference now has a DOC_MODULE name of "cogl-2.0-experimental" the
corresponding -sections.txt and -docs.xml.in files have also been
renamed to match this.

Signed-off-by: Neil Roberts <neil@linux.intel.com>

configure.ac

@@ -937,7 +937,7 @@ doc/reference/Makefile
 doc/reference/cogl/Makefile
 doc/reference/cogl/cogl-docs.xml
 doc/reference/cogl-2.0-experimental/Makefile
-doc/reference/cogl-2.0-experimental/cogl-docs.xml
+doc/reference/cogl-2.0-experimental/cogl-2.0-experimental-docs.xml
 examples/Makefile
 po/Makefile.in
 )

doc/reference/cogl-2.0-experimental/Makefile.am

@@ -9,7 +9,7 @@ AUTOMAKE_OPTIONS = 1.6
 # of using the various options.
 
 # The name of the module, e.g. 'glib'.
-DOC_MODULE=cogl
+DOC_MODULE=cogl-2.0-experimental
 
 # The top-level SGML file. You can change this if you want to.
 DOC_MAIN_SGML_FILE=$(DOC_MODULE)-docs.xml