Support for rendering INLINE layers with layer attributes (items)

[tamas]

This change would add support for using the attributes of the inline features when rendering the layer (eg. for supporting LABELITEM and CLASSITEM or attribute bindings) The item names have to be specified by using a PROCESSING parameter as follows:

LAYER

NAME "INLINE" TYPE POINT PROCESSING "ITEMS=item1,item2,item3" FEATURE

POINTS -0.2 51.5 END

END

END

Attached a patch to implement this feature.

We might also want to add new keywords to set the values of the features explicitly or use the TEXT parameter to split a comma separated list into the values in case if "PROCESSING ITEMS=" is specified, like:

FEATURE

POINTS -0.2 51.5 END TEXT value1;value2;value2

END

[tamas]

A more generic approach

[tamas]

Applied a fix for the potential memory issues r8604