Add all moment static functions to deprecated global export

Fixes #1239
Fix plural function for Polish language

Current version:
moment.duration(112, "years").humanize(); // 112 lata
moment.duration(213, "years").humanize(); // 213 lata

New version:
moment.duration(112, "years").humanize(); // 112 lat
moment.duration(213, "years").humanize(); // 213 lat

Real examples:
https://pl.wikipedia.org/wiki/Lista_najstarszych_ludzi_w_Polsce
Update tests for Polish language
correct the command to install grunt
Merge pull request #1296 from maiis/develop

correct the command to install grunt
Merge pull request #1264 from ichernev/bugfix/deprecated-export-static-methods

Add all moment static functions to deprecated global export
fixing lb linting
fix conflict between makeGlobal PRs
Add 2 additional tests for Polish language
Merge pull request #1292 from And-re/patch-2

Fix plural function for Polish language
simplifying diff. Fixes #1227
made tokens strict in strict mode
fixing JS hint errors for strict-tokens
Add quarter 'q' to format string
Change quarter format string to upper case Q
change name of quarterOfYear to quarter
Merge pull request #1311 from ericstob/develop

Add quarter 'q' to format string
Merge pull request #1303 from icambron/strict-tokens

Strict tokens making strick parsing stricter
Merge pull request #1302 from icambron/fix-dst-calendar

simplifying diff
Added serbian (rs) translation.