Revert "Disable payment protocol pending further assessment and potential rework."

This reverts commit 5967654730541a5598cb6005d7a05ef744efebc0.

Conflicts:

	src/qt/bitcoin.cpp
[Qt] ensure payment request network matches client network

- replaces checks in SendCoinsDialog::handlePaymentRequest() that belong
  to PaymentServer (normal URIs are special cased, as only an isValid
  check is done on BTC addresses)
- prevents the client to handle payment requests that do not match the
  clients network and shows an error instead (mainly a problem with
  drag&drop payment requests onto the client window)
- includes some small comment changes also
don't send feeless transactions

(cherry picked from commit 9a2f7a86fca6e243db7745cb1b15b35ce1b97b2e)
Revert "remove unit tests for new fee mode"

This reverts commit 78ed897c4adf021c30cdf10eebf4663f12f78fd1.
remove unit tests for old fee mode
adapt rpc tests to mandatory fees
patricklodder's pgp keys
fix syntax in gitian-downloader yml files
Merge pull request #556 from patricklodder/1.7.2-pgp

patricklodder's pgp keys for gitian
Merge pull request #557 from patricklodder/1.7.2-fix-gitian-downloader

[minor] fix syntax in gitian-downloader yml files
Update bitcoin_ko_KR.ts

Reflect changes of "src/qt/locale/bitcoin_en.ts" (<location line=""/> included.) and translate All. but It's not perfect.

Question: Am I doing the right way? if not, please 'closed' and give me some advice.
Revised payment request handling to use genesis block hash instead of network name.
Merge pull request #559 from nameEO/patch-1

Update bitcoin_ko_KR.ts
Merge pull request #553 from leofidus/1.7-nozerofee

Don't send feeless transactions
Merge pull request #560 from rnicoll/1.7.2-dev-payment

Re-enable payment protocol
l10n update
Remove build-time no-IPv6 setting

The year is 2014. All supported operating systems have IPv6 support,
most certainly at build time (this doesn't mean that IPv6 is configured,
of course).

If noone is exercising the functionality to disable it, that means it
doesn't get tested, and IMO it's better to get rid of it.

(it's also not used consistently in RPC/boost and Net code...)
Removed LevelDB changes

Syntax Highlighting
Better std exception logging for CAddrDb
Use correct Qt tools in Gitian Linux build