Fixing Test For Data not fitting in a block

    * Added additional check for data length before writing to block
    * Fixed the "exceedingBlockSizeTest"
Merge branch 'Fix_BrokenTest_For_DataSizeExceedingBlockSize'

Conflicts:
	src/main/java/de/jhoff/dmap/DMapBuilder.java
	src/test/java/de/jhoff/dmap/DMapBuilderTest.java
DMapBuilder Update : Adding Info in Global Trailer

    *   Updated DMapBuilder to store first key of a block along
        with the block offset info in the global trailer. This
        is to allow DMap to efficiently query for a key.

    *   Updated DMapBuilderTest to verify the latest changes
Cleaning up of branches