Increase required Perl version.

Version 5.8 might be supported too, but I do not have any such
installation to test it.
Disable version check.

The trouble is that the versioncheck macro does not compile on c++11.
One solution would be to drop -xc++ option and hope gcc will correctly
recognize the language. Nevertheless, the real versioncheck should
happen in morphodita_perl.cpp, which is not passed right -D arguments by
build.pl anyway.
Finalize CPAN package build scripts.
Update CPAN package documentation.
Do not write result in tagger_accuracy.cpp.
Add version info to MorphoDiTa API.
Add generic_morpho_encoder.
Make all morpho implementations consistent.

- When analyzing, always start with dictionary and call analyze_special
  only if dictionary lookup fails.
- Allow numbers to end by . (but disallow 4..).
Add generic_elementary_features for the tagger.
Remove english_elementary_features.

The generic_elementary_features is a strict superset and English model
was never released publically.

Nevertheless, we keep the value of tagger_ids::ENGLISH3 (which is now
removed) unassigned, so that if some old model is around, it cannot be
loaded (instead of loading and crashing, or loading and producing wrong
results).
Join create_classes and encode_dictionary binaries.

The create_classes functionality moved to morpho_dictionary_encoder.
Rename czech-morfflex to czech-morfflex-pdt in docs.
Rename english-ptb to english-morphium-wsj in docs.
Update Czech model names and accurracy.
Update English model names and accuracy.
make rules matching ^ and + in English lemmas stricter.

The + is allowed only at end, ^ is allowed only at end or
followed by [A-Za-z][-A-Za-z]* .
Fix typo bug.
Pass all C_FLAGS in linking when -flto is on.
Rename bindings/{JAVA,PERL,PYTHON} to README.{JAVA,PERL,PYTHON}.

On case insensitive file systems these files collided with directory
names.
Minor Perl CPAN updates.