v0.19

• added code to use a locally installed Alpino parser

• added code to use a remote Alpino Server

• added code to use (remote) timblservers and mbtservers for alle modules
  using JSON calls. Stil experimental.

• several code refactoring and small fixes:

  • memory leaks
  • using NER files in non-standard locations
  • bug fixes for some corner cases.

• frog.*.debug files are cleaned up after 1 day.