Allow arbitrary number of milliseconds in iso format

According to the standard (I'm not sure actually), arbitrary number of
subsecond precision digits can be specified. Read all of those and ignore
everything after the third. This makes sure that iso formats actualy consume
the whole string.
Fixed iso is_valid tests

In iso date-time format time is always separated by date with 'T', so make sure
all tests that expect to go through the iso parser have a 'T'.
Merge pull request #1213 from ichernev/bugfix/allow-arbitrary-ms-iso-format

Allow arbitrary number of milliseconds in iso format
Merge pull request #1212 from ichernev/bugfix/iso-is-valid-tests

Fixed iso is_valid tests
adding missing semicolons
fix spelling error in tagalog test
Welsh translations
Welsh translation tests
Update and rename cy-gb.js to cy.js
Update and rename cy-gb.js to cy.js
Merge pull request #1215 from robgallen/develop

Welsh language support