ariketa: bash example code quickloader for presentations

source ariketa.sh

To load ariketa, source it into the bash session you wish to use for the
presentation:
    # load examples from ariketa/config/examples.sh
    source ariketa.sh

    # load example file specified as argument
    source ariketa.sh filename.sh

When an example is displayed, it may be edited like any command line and
executed normally by pressing enter.  Use the following key bindings to
navigate through your examples:

    alt-H:     display this USAGE text

    alt-w:     load previous example
    alt-e:     load next example
    alt-a:     reload current example
    alt-h:     display current example with syntax highlighting

    alt-W:     load previous example without clearing the screen
    alt-E:     load next example without clearing the screen
    alt-A:     reload current example without clearing the screen

    alt-s:     side by side diff of previous and current example
    alt-S:     side by side diff of prev/cur examples with highlighting
    alt-P:     toggle between ariketa PS2 header and original setting

To load examples into ariketa, edit the 'examples.sh' file in the
'config' directory.  This file should be a sourceable bash script which
creates an indexed array named '_examples', whose elements have values
beginning with a tag, delineated from the example itself by a ':' character
followed by a newline.  An sample config is located in
'config/examples.sh.sample'.