Added test to verify that an endpoint properly empties HashMaps in
Matcher and SweepDeduplicator.
Fixed a bug where the length of the payload was miscalculated
Added possible response codes for requests to the documentation.
Endpoint now also acknowledges responses if the are a duplicate.
Fixed the expectations the test has from the program. The program was
correct.
Matcher no longer remembers piggy-backed responses, and therefore there
memory can be reclaimed.
The BlockwiseLayer now keeps the same token for all blocks of an
exchange.
Changed level of log statement from severe to fine.
The Matcher of a server is now able to proberly remove NON notifications
from its HashMap when either a CON notification is sent or the observe
relation gets canceled.
Converted test case for memory leaking hashmaps into a proper JUnit
Test.
The server now cancels an observe relation if a request has the observe
option set with any nonzero value (Before it would have only canceled it
if the value was 1). This behavior is requested by observe-14 chapter
4.1.
Fixed a bug where a CoapObserveRelation object did not remember over
which (client) Endpoint the relation had been established with the
server and had later used the default endpoint in attempt to proactively
cancel the relation. Now, the CoapObserveRealtion object correctly uses
the same (client) Endpoint to establish and cancel observe relations.
Extended a test and fixed a bug where the server-side matcher did not
remove entries (for NON notifications) from the HashMap exchangesByMID
after an observe relation had been proactively canceled.
Dealt with issue #7 (Block2 random access bypass for GET). Users can now
create requests that only retrieve a single block from the destination.
Merge branch 'memorytest' of https://github.com/Lanterm/californium into Lanterm-memorytest

Conflicts:
	californium-core/src/test/java/org/eclipse/californium/core/test/ResourceAttributesTest.java
Corrected de-register Observe option to 1.
Fixed Observe check 4 (CO04).
Minor style fixes.
Merge branch 'Lanterm-memorytest'
Fixed duplicate observe relations.