Fix memory leak due to softmasks.

A user (sebblonline) reports a problem when rendering the 300Meg
document downloadable from:

 http://www.mitsubishicarbide.com/EU/de/product/epaper/index.html

(7th icon on the bottom). Memento builds report that softmask objects
are leaked.

Tracing these it appears that the handling of softmasks in
pdf_run_xobject is not quite nested right. Fixing this reveals another
problem with clipping paths being doubly removed. Adding a gsave/grestore
pair solves this and leaves us with a well behaved program.
Add '-' as a option for stdout to mudraw
Fix problem with object dirty flag

There is the possibility of marking an object dirty via one indirection
and testing it via another. This patch ensures that is handled
correctly. The scenario occurred within calc.pdf and stopped the update
of the display field.
Update thirdparty.txt to include curl
ios: Clean up project file.

Strip stupid project build settings.
Add proper "make generate" target that uses the 'macosx' sdkroot.
Rewrite cross compile build script to be more future proof.
Separate command and coordinate arrays in fz_path structure.
Bug 694567: prevent double-free in pdf_open_raw_filter

If opening a filter in pdf_open_crypt throws, the stream is closed in
the used fz_open_* method and thus mustn't be closed again.
support jpegtables for TIFF images

This is required e.g. for 2314 - jpeg tables in tiff.xps.

This folds fz_open_resized_dct back into fz_open_dct instead of adding
further variations for calls with and without the jpegtables argument.
support /Alternate colorspace for ICC based

This progresses among others Bug689803.pdf and
Alternate_colorspace_for_ICCBased_not_supported.pdf
correctly set indexed colors in pdf_set_color

Required for 1879_-_Indexed_colors_wrongly_converted.pdf

Also, removing broken code in the same place (where mat->v[] is
overwritten right after being set in the L*a*b* case).
tolerate xobjects with invalid colorspaces

This fixes 2258_-_invalid_transparency_group_colorspace.pdf
Attempt to fix reflow.
Fix various compile warnings spotted by the cluster.
prevent heap underflow in pdf_read_new_xref
Android: remove use of Bitmap holder and avoid memory churn

Now use one-time allocation of page-sized bitmaps
iOS: avoid XCode's passed environment breaking the "generated" build
iOS: use the background thread for CGDataProviderCreateWithData's callback
iOS: split the classes into separate files