Add support for Xilinx Spartan-3A(N) FPGA Starter Kit (up to bitgen f…

[imranyusuff]

…or now)

Issues (all related to edalize):

1. The device family for Spartan3A(N) is named "Spartan3A and Spartan3AN" which have spaces. Edalize does not yet emit {family} with quotes so without escaping the double quotes inside the quoted string, there will be multiple argument error.

2. I can only program the FPGA if, within the generated pgm file, I add the switch -onlyFpga on the program command. Suggest to add parameter program_args to allow arbitrary switches to be specified.

[olofk]

Great! Thanks. I took the opportunity to fix this in the ISE backend (olofk/edalize#360). Would you mind testing if it works without the double quoutes using this fix?

As for programming, we could look into a patch to fix that too later on