Bitfile versioning

[Ajstros]

Add bitfile versioning functionality to FPGA class and DDR3.save_data and DDR3.data_to_names methods.

• Bitfile version can be found in Endpoint GP_BITFILE_VERSION, it will be given as a 6-digit number (e.g. 20514 -> v02.05.14)
• Bitfile version is saved to the FPGA attribute bitfile_version and printed with other initialization data when FPGA.init_device() is run

Edit:

Later commits on this branch also add an append optional parameter to DDR3.save_data() to allow the user to choose between overwriting any pre-existing file with the same name, and appending the new data to that file.

[Ajstros]

Working as expected now

[lucask07]

I'm not certain how the default parameter self.fpga.bitfile_version will behave if DDR3 is instantiated before the FPGA is initialized. The preferred usage might be that the bitfile_version is determined from the h5 file. Doing so will allow for offline data analysis to be done without an FPGA instance.

[Ajstros]

The code has been updated, as outlined below. The idea is that we will pass in the bitfile version number from the .h5 file when we call data_to_names. This keeps data_to_names indepedent from .h5 files, so that we keep the option of reading DDR data without saving to a .h5 file open.

[Ajstros]

The code has been updated to use None as the default. This allows old code to still use DDR3.data_to_names without needing to be updated for the new parameter.