Retrieve embedded ICC profile render intents

This really needs to be controlled by preference, but in the interim,
support for embedded render intent is now available.  PD still defaults
to perceptual intent at present, but this can be modified by commenting
out a single line of code.

There are multiple theories on whether or not embedded profile intents
should be used (see
https://developer.mozilla.org/en-US/docs/ICC_color_correction_in_Firefox,
for example).  PostScript workflows do not typically honor embedded
intents
(http://fieryforums.efi.com/showthread.php/835-Rendering-Intent-Control-for-Embedded-Profiles.),
because the user may not be using the color profile for its original
intent - e.g. proofing CMYK data on-screen before printing.  Blindly
using the embedded intent can lead to subpar results, which is why
embedded intent is almost always ignored, save for printing.

Once PD gets a reworked print dialog with detailed color management
support, I'll revisit this, but I wanted to add support for retrieving
embedded intents while the ICC spec was fresh in my mind.