First round of changes for fvec PostFile.
Minor refactoring.
Call chunk close with chunkIdx.
Rename NewChunk.new_close
Create multiple chunks of size Vec.CHUNK_SZ.
Tiny refactoring of totalChunks calc.
Added alwaysPutToDKV argument to close().
Kept the old default behavior, though.
Use espc() everywhere instead of _espc so that overriding it works in derived classes.

Make chunkIdx() more debugger friendly by conditionally breaking out the assert on
it's own line.
It turns out that Parse2 really really wants things to be ByteVec.
So UploadFileVec now creates a ByteVec.
Delete files associated with a wrong approach to the problem.
Wipe out transient stuff at close().
UploadFileVec uses FileVec instead of ByteVec; most code gets removed.

FileVec can have it's _len set during close.
Remove getChunkSz back to CHUNK_SZ so the compiler gets a constant.
Remove espc() back to _espc so no v-call in inner loops.
Use Arrays.copyOf instead byte-by-byte copy.
Use FileVec.CHUNK_SZ instead of Vec.CHUNK_SZ.
Shrink CHUNK_SZ to an int.
Restore close() behavior.
Add comment
Fix broken trailing block in UploadFileVec

Move input stream from Frame to UploadFileVec.
Handle 1-off larger final block
Merge branch 'master' into tomk-postfile
fix bug in GLMGrid throttling.  Make RPCs call tryComplete on local tasks.