More consistent sendpfast API (breaking)

[gpotter2]

• improve consistency in APIs

The behavior of:

sendpfast(Ether(), loop=1)

is now equivalent to:

sendp(Ether(), loop=1)

where previously it would have been:

sendp(Ether(), loop=0)

Calling @p-l- for review

[codecov]

Codecov Report

Merging #4157 (2130ee3) into master (4fefbb0) will increase coverage by 0.02%.
Report is 3 commits behind head on master.
The diff coverage is 57.14%.

@@            Coverage Diff             @@
##           master    #4157      +/-   ##
==========================================
+ Coverage   81.76%   81.78%   +0.02%     
==========================================
  Files         330      330              
  Lines       76315    76334      +19     
==========================================
+ Hits        62399    62431      +32     
+ Misses      13916    13903      -13     

Files	Coverage Δ
scapy/supersocket.py	75.66% <100.00%> (ø)
scapy/sendrecv.py	87.97% <50.00%> (-0.25%)	⬇️

... and 15 files with indirect coverage changes