toBits(): Round up len to nearest byte instead of radix.

When toBits() is called without specifying a length, calculate the
length with bitLength(), which rounds up to the nearest byte instead of
multiplying limbs by radix, which rounds up to the nearest radix.  This
fixes an issue where converting a 256-bit value to a bitArray and then
calling bitArray.bitLength() on it, gave 264.
Fix ecdsa sign and verify.
Add ecdsa test vectors.

P-192,SHA-256 and P-224,SHA-256 are commented out since the computed S
values don't match. FWIW, cryptopp appears to give the same results as
this library for those combinations.
Enable ecc and generate sjcl.js.
Clamp hash bit length to curve bit length.

The P-192,SHA-256 and P-224,SHA-256 tests now pass.
correct ecdsa; try both ways
merge 00e88b08e683624e0acbf621862e2f3854fdd176
fix bugs introduced by those changes...
import newer closure compiler and set annotations so that it doesnt complain; then change opacify scripts so they dont eat the annotations