readfmtdata needs identical D-struct

[jmsaurel]

readfmtdata concatenate D structures from each readfmtdata_* format specific function.

The required structure for a given NODE data is composed of 3 tables : D.t, D.d, D.e and D.CLB.
If a data format do not contain error field, it should return a D.e structure with NaN and the same size as the D.d structure.

[jmsaurel]

Codes to check/modify :

• readfmtdata_campbell
• readfmtdata_earthworm
• readfmtdata_meteofrance
• readfmtdata_miniseed
• readfmtdata_naqs
• readfmtdata_porkyasc
• readfmtdata_rinex
• readfmtdata_sqltable