Add Linux sendKeyboardInput

This implementation has several problems.
1) It only really deals with Latin1 characters. This is the same as the
Windows implementatino.
2) It doesn't handle modifier keys at all. This is also a problem with
the Win implementation.

This is an interim solution until a unified strategy can be made for
both Windows/Linux.

src/tabcontrollers/keyboardinput/KeyboardInputX11.cpp

@@ -3,10 +3,7 @@
 #include <X11/Intrinsic.h>
 #include <X11/extensions/XTest.h>
 #include <unistd.h>
-
-// Used to get the compiler to shut up about C4100: unreferenced formal
-// parameter. The cast is to get GCC to shut up about it.
-#define UNREFERENCED_PARAMETER( P ) static_cast<void>( ( P ) )
+#include <array>
 
 namespace keyboardinput
 {
@@ -44,8 +41,16 @@ void sendKeyPress( const KeySym keySymbol, const KeySym modifierSymbol )
 
 void sendKeyboardInput( QString input )
 {
-    // noop
-    UNREFERENCED_PARAMETER( input );
+    std::vector<char> characters = { 0 };
+    for ( const auto& character : input )
+    {
+        characters.push_back( character.toLatin1() );
+    }
+
+    for ( const auto character : characters )
+    {
+        sendKeyPress( XStringToKeysym( &character ), noModifier );
+    }
 }
 
 void sendKeyboardEnter()