convert tabs to whitespace in bitrpc.py

This is a minor change to bitrpc.py to conform with the formatting of
the other python source code in the repo.
Fix typo in doc/build-unix.md regarding building without UPnP
[Qt] show number of in/out connections in debug console
MainNet is the special case for the GUI
Minor code cleanup: remove indentation

This indentation should have been stripped out when AreInputsStandard was made a top-level function instead of a CTransaction method.
Merge pull request #3823

89ec3a2 MainNet is the special case for the GUI (jtimon)
Merge pull request #3817

e935293 Minor code cleanup: remove indentation (Mark Friedenbach)
Merge pull request #3773

947e23d Fix typo in doc/build-unix.md regarding building without UPnP (Rune K. Svendsen)
Merge pull request #3751

b881100 convert tabs to whitespace in bitrpc.py (Bryan Bishop)
Merge pull request #3685

8e29623 [Qt] show number of in/out connections in debug console (Philip Kaufmann)
qt: Adjust BLOCK_CHAIN_SIZE to 20GB

This increases the space requirement for selecting a data directory in
the UI.
As suggested by @bardiharborow, fixes #3830.
add --enable-debug for configure
Merge pull request #3833

f5f157b add --enable-debug for configure (daniel)