Wrapper around Charniak's parser, allowing to use it one sentence at a time while the engine is running. It parallelizes parsing by using a pool of parser processes in the background. More importantly, it gracefully handles inputs for which the Charniak parser crashes or hangs.

Usage:

1. As a library: call init() first, then parse_sentence(txt) for each sentence. At teardown, you might want kill_parsers()
2. As a standalone web service: just run it (port and hostname hardcoded below); for every line of input that you send to the socket, you receive a line of output, i.e. the parsed sentence.