Wire documentation is outdated and contains multiple errors

[alibenpeng]

For example:

• There is no function setWireTimeout() anymore. The function is now called setTimeout() and takes milliseconds, not microseconds, as its first argument.
• There is no documentation for either setSDA() or setSCL() functions.
• The buffer size limit is no longer 32 bytes. At least not on every platform.
• There seems to be no explanation on how to use more than one I2C bus simultaneously.