Fixes Session#when_channel_polled to properly account for 4 byte length
header, so that it waits for the complete packet to arrive instead of
processing an incomplete packet and loosing sync with server.

A new test method, gets_packet_in_two, enables testing of fragmentation
edge cases.  expect_file_transfer now takes a :fragment_len parameter,
allowing for DRY testing of common fragmentation cases like this one.
Merge pull request #26 from accardi/fix_fragmentation_download_bug

Fix fragmentation download failure
Version bump (2.1.2)
Typo
Merge pull request #29 from jumph4x/master

Teeny tiny typo :)
Fixed a minor typo
Merge pull request #30 from dharamgollapudi/patch-1

Fixed a minor typo
Update README.rdoc

Maintenance mode note in readme.