DatePicker improvements

[raveclassic]

This is a copy.

• get rid of moment.js and ISO-strings, use native Date type
• and use standard (or polyfill), see related:
  https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DateTimeFormat and https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Date/toLocaleDateString
• replace onmousedown with onclick, don't block input blur
• remove imperative props methods from DateInput ('openDatePicker', 'closeDatePicker') - isOpened state should be handled on DatePicker level, not on Input's
• DateInput should not be responsible for any kind of formatting, consider using plain Input (see SymbolSuggest)
• do not use calendarTheme prop - it breaks pure-rendering
• rename fieldComponent to Input
• use formatter functions instead of format strings for moment
• do not handle validation
• remove all explicit sizes from dx-components css (paddings, margins, widths etc.)
• do not handle state in Calendar (move to datepicker)
• moment.clone() seems to break pure-rendering everywhere
• research react perf
• render calendar/month as css-table
• accept all child component classes as props (research DI)