Script documentation generation and UML support (#992)

Documentation is now generated by invoking a shell script
which takes care of all the plumbing.
There is now also support of inlineing PlantUML syntax with
Doxygen. This inlining takes the form of
@startuml{imagename.png}
'PlantUML specific syntax'
@enduml
The inlineing can be made in C syntax comment blocks.
Doxygen will then include the generated UML diagram when
rendering the HTML documentation.
All generated images will be placed under Documentation/img
which is the default search path for Doxygen.

Doxyfile

@@ -220,7 +220,8 @@ TAB_SIZE               = 4
 # "Side Effects:". You can put \n's in the value part of an alias to insert
 # newlines.
 
-ALIASES                =
+ALIASES                = "startuml{1}=\image html \1\n\image latex \1\n\if DontIgnorePlantUMLCode"
+ALIASES               += "enduml=\endif"
 
 # This tag can be used to specify a number of word-keyword mappings (TCL only).
 # A mapping has the form "name=value". For example adding "class=itcl::class"
@@ -731,7 +732,7 @@ WARN_FORMAT            = "$file:$line: $text"
 # messages should be written. If left blank the output is written to standard
 # error (stderr).
 
-WARN_LOGFILE           =
+WARN_LOGFILE           = doxygen.log
 
 #---------------------------------------------------------------------------
 # Configuration options related to the input files
@@ -2289,3 +2290,6 @@ GENERATE_LEGEND        = YES
 # This tag requires that the tag HAVE_DOT is set to YES.
 
 DOT_CLEANUP            = YES
+
+# PlantUML executable
+PLANTUML_JAR_PATH      = $(PLANTUML_JAR_PATH)