Icon repository for the applications

All of the icons, separated by themes are included in this
directory. These icons are built into .zip files, and re-ordered /
packed for efficiency reasons based on our UI configuration by the
postprocess/CustomTarget_images.mk.

An icon theme does not need to contain all images, since these can be
layered one on top of another.

In general the layering is done like this:

<leaf theme>
breeze
colibre
tango

How to add a new image set:
---------------------------

- Create a directory for it here (let's call it e.g. new_set)

  FIXME: It is important to use an underscore '_' to delimit more words.
         scp2 compilation crashes when using a dash '-'.
         It evidently splits the name into two strings.
   ^ It's probably not true anymore with filelists.
   ^ if this gets changed, IconThemeSelector::SetPreferredIconTheme needs to change too

- Add its name (new_set) to WITH_THEMES variable in configure.ac

- The fallback for particular icons is defined be packimages_CUSTOM_FALLBACK_1
  in packimages/CustomTarget_images.mk


How to add a new icon for a new command:
----------------------------------------

- Assume you defined a dispatch command in officecfg like the following:

  in officecfg/registry/data/org/openoffice/Office/UI/CalcCommands.xcu

    <node oor:name=".uno:OpenFromCalc" oor:op="replace">
        <prop oor:name="Label" oor:type="xs:string">
            <value xml:lang="en-US">~Open...</value>
        </prop>
        <prop oor:name="Properties" oor:type="xs:int">
            <value>1</value>
        </prop>
    </node>

  Here, you need to define a property named "Properties", with its value set
  to 1 so that the icons show up.

- Now, you need to add 2 new icon images under icon-themes/colibre/cmd/, one
  for the large size and one for the smaller size.  The name of each image
  must be lc_<command name>.png and sc_<command name>.png.  Here, the command
  name is the name given in the above .xcu file without the ".uno:" prefix and
  all its letters lower-cased.  In this example, the file names will be
  lc_openfromcalc.png and sc_openfromcalc.png.  Note that you need to add new
  images to the colibre theme for them to show up in any themes at all.

How to call optipng to optimize size:
---------------------------

8 bit palettes are on the slow path for quartz/svp/gtk3 so avoid using palettes with...

$ optipng -nc <file>