Adding static pattern validation method to Validators
Adding a directive for the pattern validator
Applying clang-format rules to modified files
Updating public api spec for new pattern validator
Adding pattern validator to public api guard tool
For #5411Closes#5561
BREAKING CHANGE
All private exports from 'angular2/src/core/{directives,pipes,forms}' should be replaced with 'angular2/src/common/{directives,pipes,formis}'
Closes#5153
