v1.0.0

Since the API has been pretty stable and no real bug reports have been filed for a long time, the project could now be considered stable in the sense that we now will follow semantic versioning rules.

• Add callback for NMT slaves (#158)
• More info in debug output when adding PDOs (#162)
• Add unofficial support for using a custom CRC for block transfers (#157)
• Fix SDO communication error printout (#160)