#343 Yet another ZIP support patch

[Sergio Baldoví]

This patch was developed after [patches:#157], but somehow I lost interest and forget to share (sorry!). I totally endorse [patches:#342] as the best approach, it's simpler and less error prone.

Features:

• Use zlib for ZIP decompression using the ZIP central directory.
• No content browser, i.e., open first supported file.
• Have an API that could be potentially used by a content browser.

[Fredrick Meunier]

Committed on the feature-53-zip-support branch for investigation and hopeful merging to trunk.

[Fredrick Meunier]

Discussion has been under [patches:#342] but I propose merging this to trunk next weekend barring feedback to the contrary.

[Fredrick Meunier]

Merged to trunk from feature-53-zip-support branch in [r5718].