Fixed selection intersection bug.
Added more Read BP timer instrumentation (this time including writeblock
reads, which were not timed before because they weren't used for
transformed reads).
Added .project and .cproject to gitignore to avoid spurious "local
modifications" state in Eclipse.
Added support in the ADIOS common/read layer for sub-PG writeblock read selections.

This includes adding new fields ot the writeblock struct (is_sub_pg_selection,
element_offset, nelements), modified code to support writeblock selection
copying and testing for equality, and of course correct interpretation by
the Read BP transport method.
Modified the constructors for raw read requests in the Transforms layer
to use writeblock selections.

Also modified all existing transform plugins
to use this new API (this was trivial; pg_reqgroup->raw_varblock simpy
changed to pg_reqgroup as the first argument, since the raw varblock
always came directly from the pg_reqgroup).

NOTE: use the macro RAW_READS_USE_WRITEBLOCK
just above the raw read request constructor
implementations to toggle the new writeblock-based read selection
code (undefine to revert to bounding boxes).
Added example program to test sub-PG writeblock read selection.
Added timer init/finalize to some example code tests