Let -zapwallettxes recover transaction meta data
miner: indentation fixes, remove for (;;)

- change a for (;;) into while (true), as we nowhere else use the first
- init nNonceFound to 0
- fix indentation in BitcoinMiner try/catch block
Refactor proof of work related functions out of main
move pow constants to chainparams
replace 3 separate calls to WSAGetLastError() with 1
remove -tor compatibility code (only allow -onion)

- exit, if -tor option is found and give error to user
[Qt] fix links in about window not opening

- closes #4402
Merge pull request #3674

77cbd46 Let -zapwallettxes recover transaction meta data (Cozz Lovan)
Merge pull request #4169

0655fac miner: indentation fixes, remove for (;;) (Philip Kaufmann)
Merge pull request #4130

1c750db remove -tor compatibility code (only allow -onion) (Philip Kaufmann)
Merge pull request #4403

5fbb4c9 [Qt] fix links in about window not opening (Philip Kaufmann)
Add dependencies for Mac OSX gitian builds
Consistent lettering
Update .gitignore

Removing old file ignores so they show up in `git status`
Merge pull request #4408

e3aedba Consistent lettering (Whit J)
Merge pull request #4406

b79f59b Update .gitignore (Drak)
Merge pull request #4404

e9f2460 Add dependencies for Mac OSX gitian builds (Drak)
Merge pull request #4390

6dc90ed replace 3 separate calls to WSAGetLastError() with 1 (Philip Kaufmann)
Merge pull request #3839

fd704c7 move pow constants to chainparams (jtimon)
df852d2 Refactor proof of work related functions out of main (jtimon)
Make CBlockIndex a subclass of CBlockHeader