fix MSVC (2015) libcommuni link errors, and use correct warn flag (#44)

* use fixed libcommuni submodule

* warn flag -W4 should be used for MSVS instead of -Wall, move libcommuni
define and include together

* define correct warning flags for MSVC and else

.gitmodules

@@ -1,3 +1,3 @@
 [submodule "lib/libcommuni"]
 	path = lib/libcommuni
-	url = https://github.com/communi/libcommuni
+	url = https://github.com/hemirt/libcommuni

chatterino.pro

@@ -9,6 +9,7 @@ CONFIG  += communi
 COMMUNI += core model util
 CONFIG  += c++14
 
+DEFINES += IRC_NAMESPACE=Communi
 include(lib/libcommuni/src/src.pri)
 
 greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
@@ -17,13 +18,16 @@ TARGET   = chatterino
 TEMPLATE = app
 
 DEFINES += QT_DEPRECATED_WARNINGS
-DEFINES += IRC_NAMESPACE=Communi
 
 # Define warning flags for Chatterino
-QMAKE_CXXFLAGS_WARN_ON = -Wall
-QMAKE_CXXFLAGS_WARN_ON += -Wno-unused-function
-QMAKE_CXXFLAGS_WARN_ON += -Wno-switch
-QMAKE_CXXFLAGS_WARN_ON += -Wno-deprecated-declarations
+win32-msvc* {
+    QMAKE_CXXFLAGS_WARN_ON = -W4
+} else {
+    QMAKE_CXXFLAGS_WARN_ON = -Wall
+    QMAKE_CXXFLAGS_WARN_ON += -Wno-unused-function
+    QMAKE_CXXFLAGS_WARN_ON += -Wno-switch
+    QMAKE_CXXFLAGS_WARN_ON += -Wno-deprecated-declarations
+}
 
 # do not use windows min/max macros
 win32 {