Code cleanup and use same syntax on the entire project

Initial code cleanup

More code cleanup

Cleanup more code

Cleanup Dot11 code

Fix OSX build issue

Cleanup examples

Fix ref and pointer declaration syntax

Fix braces

tests/src/ipv6address.cpp

@@ -12,7 +12,7 @@ using namespace Tins;
 
 const uint8_t empty_addr[IPv6Address::address_size] = { 0 };
 
-void test_to_string(const std::string &str) {
+void test_to_string(const std::string& str) {
     EXPECT_EQ(str, IPv6Address(str).to_string());
 }