Fix null pointer on null string

- Updated asString in JsonPrimitive so null string values will not
throw null pointers
- Removed an unnecessary get() in JsonObject
Merge fix for npe by johnygoods
use less aggressive escaping, we don't want every character outside the ascii range represented as a \u code
updated documentation for deploying to sonatype
commons-lang was needed after all
override addAll method to allow adding elements from a Collection
fix versions
better exception message
release jsonj-0.8
snapshot for next release
Update README.textile
npe
exclude junit
handle null values in dictionaries more gracefully during serialization (silently drop the key if value is null)
modify behavior of array builder to support collections in a sensible way. This changes the behavior of 
array(anotherJsonArray). Previously you'd get an array with a single array element in it. Because a json array is just another collection, it now inherits the behavior and you get an array of elements in the collection. If the elements are JsonElements, they are added as such. Otherwise it attempts to interpret them as primitives.
escape tabs during serialization (some parsers don't like tabs)
update documentation
fix addAll to not wrap JsonElements with a primitive(..)
comment added
add hamcrest dependency