fromBuffer convenience function for pubkey
also have keys and messages
"function" not used
typo
support reading varInt nums up to js precision

Javascript only supports 64 bit floating points, which have uint precision up
to Math.pow(2, 53). We now support reading variable sized numbers up to that
size. If the number is bigger than that, then we need to use BN.
readVarInt -> readVarIntNum

"varInt" refers to the varInt object, which is not actually implemented yet.
This function should therefore really be called readVarIntNum.
add readVarIntBuf function

...will be useful for new Varint class
varIntNum
varInt -> varint

I don't like having to capitalize things unnecessarily
extra semicolon
missing semicolon
Varint class

...will be useful in transactions. Note that we already have a primitive
understanding of Varints in the BufferReader and BufferWriter classes. However,
the new Varint class is a varint object which actually depends on BufferReader
and BufferWriter for reading and writing varints. This class is for keeping
track of the raw buffer that is read in from a buffer.
disable examples in browser
expose varint in bitcore bundle
add bn support to varint class
Txin
Txout
"undefined"s are unnecessary
throw error if hashbuf is not 32 bytes
sign, verify convenience functions