Finish beta-version of liveattrs 'moving data window'

Merge pull request #27 from czcorpus/data-window

Implementing a moving data window functionality for liveAttrs:

Merge pull request #21 from czcorpus/sim_frq_srch_optim

Ngram proc improv., sim arf search fix

Merge pull request #15 from czcorpus/custom_data_dir_ladb

1) Handle missing attribute position info, 2) allow custom db data dir

Merge pull request #8 from czcorpus/ngram_gen_fix

Ngram generating fix

Merge pull request #6 from czcorpus/proto_fixing

Prototype fixing

Merge pull request #5 from czcorpus/misc_fixes

Add a specific endpoint for dict. search

Fix - missing select arg

Fix import process, fix sim. freq. search

Merge pull request #1 from czcorpus/ngram_build_upd

Improved implementation of ngram extraction: