Reimplement click-to-pay links. Add OSX support.

Switch to using Qt's QLocalServer/QLocalSocket to handle bitcoin
payment links (bitcoin:... URIs)

Reason for switch: the boost::interprocess mechanism seemed flaky,
and doesn't mesh as well with "The Qt Way"

qtipcserver.cpp/h is replaced by paymentserver.cpp/h

Click-to-pay now also works on OSX, with a custom Info.plist
that registers Bitcoin-Qt as a handler for bitcoin: URLs and
an event listener on the main QApplication that handles
QFileOpenEvents (Qt translates 'url clicked' AppleEvents into
QFileOpenEvents automagically).

bitcoin-qt.pro

@@ -2,6 +2,7 @@ TEMPLATE = app
 TARGET = bitcoin-qt
 VERSION = 0.8.0
 INCLUDEPATH += src src/json src/qt
+QT += network
 DEFINES += QT_GUI BOOST_THREAD_USE_LIB BOOST_SPIRIT_THREADSAFE
 CONFIG += no_include_pwd
 CONFIG += thread
@@ -195,7 +196,7 @@ HEADERS += src/qt/bitcoingui.h \
     src/qt/askpassphrasedialog.h \
     src/protocol.h \
     src/qt/notificator.h \
-    src/qt/qtipcserver.h \
+    src/qt/paymentserver.h \
     src/allocators.h \
     src/ui_interface.h \
     src/qt/rpcconsole.h \
@@ -264,7 +265,7 @@ SOURCES += src/qt/bitcoin.cpp src/qt/bitcoingui.cpp \
     src/qt/askpassphrasedialog.cpp \
     src/protocol.cpp \
     src/qt/notificator.cpp \
-    src/qt/qtipcserver.cpp \
+    src/qt/paymentserver.cpp \
     src/qt/rpcconsole.cpp \
     src/noui.cpp \
     src/leveldb.cpp \
@@ -385,6 +386,7 @@ macx:TARGET = "Bitcoin-Qt"
 macx:QMAKE_CFLAGS_THREAD += -pthread
 macx:QMAKE_LFLAGS_THREAD += -pthread
 macx:QMAKE_CXXFLAGS_THREAD += -pthread
+macx:QMAKE_INFO_PLIST = share/qt/Info.plist
 
 # Set libraries and includes at end, to use platform-defined defaults if not overridden
 INCLUDEPATH += $$BOOST_INCLUDE_PATH $$BDB_INCLUDE_PATH $$OPENSSL_INCLUDE_PATH $$QRENCODE_INCLUDE_PATH