Tests with bpls indicate that variable payloads are recognized

Renamed BPWriter engine to BPFileWriter

Changed WriteVariableIndex function in BP1Writer to only include a
capsule::STLVector as buffers, other capsules will need to get it from
this heap buffer.

To do:
add profiling info (time)

Now printing last variable values with bpls. 

Need to fix so payload offset is set for all variables correctly. 

Replaced vectors with map containers for Variables to avoid iterator
invalidation when adding element to a container. 

Metadata is correctly interpreted by ADIOS 1.0 bpls

To do:
Need to debug values from bpls -d option

Continued debugging BP1 Writer for a single variable write

examples/hello/bpWriter working

To do:

BPReader examples and BP1Reader class