Read*Data() wrong implemented in firmata adaptor

[gen2thomas]

Implementations of Read*Data() in firmata (and also formerly in digispark) are wrong implemented, regarding to the Kernel specification and the implementation of sys-fs driver (which uses syscall to smbus).

Read Byte (Comm==Register)
S Addr Wr [A] Comm [A] Sr Addr Rd [A] [Data] NA P
We have implemented in "ReadByteData()":
S Addr Wr [A] Comm [A] P S Addr Rd [A] [Data] NA P

Read Word
S Addr Wr [A] Comm [A] Sr Addr Rd [A] [DataLow] A [DataHigh] NA P
Implemented in "ReadWordData()":
S Addr Wr [A] Data [A] P S Addr Rd [A] [DataLow] A [DataHigh] NA P

In general most chips support both sequences, but unfortunately not all, e.g. PCA9501, which only support the "Read Byte".