Compile errors due to change in CEF API

[Adrian Schollmeyer]

Originally opened in #94.

Apparently, CEF changed the API somewhere between build 1864 and build 1085.
A few adjustments must be make to make linuxbrowser work with newer CEF versions again.

Return types must be void instead of bool:

obs-linuxbrowser/src/browser/browser-client.hpp

Line 40 in 2f7a606

 virtual bool GetViewRect(CefRefPtr<CefBrowser> browser, CefRect& rect) OVERRIDE; 

obs-linuxbrowser/src/browser/browser-client.cpp

Lines 31 to 37 in 2f7a606

 bool BrowserClient::GetViewRect(CefRefPtr<CefBrowser> browser, CefRect& rect) 
 { 
 	pthread_mutex_lock(&data->mutex); 
 	rect.Set(0, 0, data->width, data->height); 
 	pthread_mutex_unlock(&data->mutex); 
 	return true; 
 }