Get ICU 4.6 to be compiled without RTTI....

Get ICU 4.6 to be compiled without RTTI.

This is a throw-away CL. 

- Add two macros, CR_DYNAMIC_CAST and CR_TYPEID to utypes.h
- Replaces dynamic_cast with CR_DYNAMIC_CAST, which is defined as 'static_cast'
- Replaced typeid(o) with CR_TYPEID(o), 
  which is defined as '((o).getDynamicClassID())'
- Manually fix up three files (calendar.cpp, ucal.cpp and translit.cpp) where
  blindly replacing typeid with CR_TYPE id and dynamic_cast with
  CR_DYNAMIC_CAST doesn't work.

With this CL, Chrome will be built without enabling RTTI for ICU and the size
of chrome will be compared with that of chrome built with the unpatched ICU
and RTTI enabled.

See http://codereview.chromium.org/6484008/ for more details.

BUG=61514
TEST=Chrome can be built without RTTI enabled.