hdl:
- substitute FIFO for ring buffer
- change pulse repetition duty cycle to 1/500
- renamed some files to make "generic" naming

sim:
- release: add I2C simulation capabilities
- conv_pulse_gen: change testbench.vhd for simulating 1/500 duty cycle

syn:
- update project file with new files
Signed-off-by: Theodor Stana <t.stana@cern.ch>