[v0.3.0 branch] changing MentionID to i32
replacing relation_name with relation_type defined by an Enum:

To make the ACE reln names work as enum values in thrift, these string replacements
were made:   s/-//  and s/./_/
add --tagger_id argument to filter tokens to the specified tagger(s)
Merge pull request #1 from UltraNurd/v0.3.0-dev

add --tagger_id argument to filter tokens to the specified tagger(s)
bumping version number for this branch
adding Token.mention_type and MentionType and removing the two
pronouns from EntityType, so we can distinguish pronouns (PRO), noun
phrases (NOM), and proper names (NAME).

Beginning to add AttributeType, but not yet connected into anything.
Merge branch 'master' into v0.3.0-dev
updating scala Makefile to use if/VERSION
updating scala package to to v0_3_0 and making a new jar
bringing in the old streamcorpus-v0_2_0 definitions
setting up streamcorpus python package to expose Versions.v0_3_0
and have access to v0_2_0 messages for backwards compatibility.
committing the three different sets of source files
generated by thrift from the three past versions of
the streamcorpus interface definitions
separating "test" and "clean" in makefile in this branch
adding Attribute, AttributeType, StreamItem.body.attributes, and Gender
changing Attribute.type to string instead of binary
adding defaults to Language in this branch
making the python streamcorpus.make_stream_item in the v0.3.0-dev branch also generate StreamItem.body.language by default
bumping python package version to v0.3.1
getting README for cpp example into this branch
(used git checkout instead of cherry-pick, so lost the history; not important
for this one, but also not ideal.)
checking out changes from master so that we stay in sync with it