added Query.getBytes() for convenience; made slaveCoordinator send a query
for each partition of a table to the root slave; slaves now pass the
result upwards; the execution is not properly spread accross the slaves
yet; <- TODO
ChannelNode.close() does not throw IOExceptions; Slave.stop() now calls
super.close() -> fixes shutdown issue; Slave.addChild() changed to hand
new children to existing children, instead of having them replace the
existing ones;
Slave.stop() now calls clear() on directChildren and childChannels;
Added milestone3-presi files
 this is just a commit of the status quo in which the SlaveTest functions;
added degree parameter to Slave constructor to make it configurable at
instantiation; it controls the number of direct children a slave accepts,
i.e. the tree's degree, if all slave are of the same degree; alternating
degree between slaves used together has not been tested yet, neither has
the scaling of slaves;
Added constructors in ColumnReader/WriterImpl data accept Data*Stream
Added running flag in Coordinator and Leaf

This flag is checked in the stop() methods, so we do not do the shutdown
twice. (Happened because of the Shutdown hook sometimes.)
pom.xml: Added antlr 3.4 dependency and antlr-plugin
First commit of massive query / message / network rewrite

Added ANTLR bases "SQL" parser and new classes for representing a parsed
query (Query, SelectClause, WhereClause).

Added new message classes QueryMessage (contains a Query and a query id)
and TabletMassage (contains tablet data as a byte-array and a query id)
and changed Encoder and Decoder to be able to encode/decode them.
SimpleMessage is still retained but the remaining types of messages
should also be converted to the new message scheme.
QueryTest: Fixed type DOCUMENT -> Document in query
Added proper parser error handling in QL.g and QueryParser

Modified CLIClient to print the error messages.
QL.g: Changed , to OR in where clause to better reflect nature of clause
Changed encoder/decoder to allow empty payloads in SimpleMessage
QL.g: Fixed STRINGLITERAL, do not include the "" in the value
refactor; cleanup; doc; unfinished: work on handling disconnects;
First working "hack" of real query executor that obeys where clauses
Changed the way column readers/writers work

ColumnReader is an abstract base class now and there is one subclass per
primitive data-type. ColumnReader is a class that is directly used.

Both simply work with streams, so it should be extensible to a HDFS
backend.

Now it was possible to abandon the recently introduced *SliceColumn
classes.
Renamed OnDisk* columnar stuff to LocalDisc*

In future we might add Hdfs* stuff...
Merge branch 'query-network-rewrite' of github.com:aljoscha/presslufthammer into query-network-rewrite

Conflicts:
	src/main/java/de/tuberlin/dima/presslufthammer/query/Projection.java
	src/main/java/de/tuberlin/dima/presslufthammer/query/Selection.java
	src/main/java/de/tuberlin/dima/presslufthammer/transport/CLIClient.java
	src/main/java/de/tuberlin/dima/presslufthammer/transport/ChannelNode.java
	src/main/java/de/tuberlin/dima/presslufthammer/transport/Coordinator.java
	src/main/java/de/tuberlin/dima/presslufthammer/transport/Inner.java
	src/main/java/de/tuberlin/dima/presslufthammer/transport/Leaf.java
	src/main/java/de/tuberlin/dima/presslufthammer/transport/messages/Encoder.java
	src/main/java/de/tuberlin/dima/presslufthammer/transport/messages/Type.java
	src/main/java/de/tuberlin/dima/presslufthammer/transport/util/GenericHandler.java
	src/main/java/de/tuberlin/dima/presslufthammer/transport/util/QueryHandler.java