Tidy up of HttpMessage
Tidy up of HttpMessage

 - Changed to not allow to set null request/response headers/bodies, by throwing IllegalArgumentException;
 - Added/updated the JavaDoc to reflect the new behaviour;
 - Removed some statements that checked if the request body was null (and that created it if it was);
 - Fixed the JavaDoc that stated that the response header has not been read if the call "getResponseHeader().toString()" returned an empty string (which never occurred, the returned string is always non emtpy moreover it would throw a NullPointerException).

ozzyjohnson/zaproxy,profjrr/zaproxy,jorik041/zaproxy,mustafa421/zaproxy,pdehaan/zaproxy,tjackiw/zaproxy,ozzyjohnson/zaproxy,MD14/zaproxy,kingthorin/zaproxy,kingthorin/zaproxy,thamizarasu/zaproxy,efdutra/zaproxy,thc202/zaproxy,jorik041/zaproxy,veggiespam/zaproxy,Ali-Razmjoo/zaproxy,kingthorin/zaproxy,thamizarasu/zaproxy,zaproxy/zaproxy,ozzyjohnson/zaproxy,tjackiw/zaproxy,NVolcz/zaproxy,urgupluoglu/zaproxy,robocoder/zaproxy,thc202/zaproxy,UjuE/zaproxy,mustafa421/zaproxy,lightsey/zaproxy,lightsey/zaproxy,cassiodeveloper/zaproxy,lightsey/zaproxy,pdehaan/zaproxy,thamizarasu/zaproxy,gsavastano/zaproxy,MD14/zaproxy,surikato/zaproxy,thamizarasu/zaproxy,meitar/zaproxy,mario-areias/zaproxy,Ye-Yong-Chi/zaproxy,gmaran23/zaproxy,cassiodeveloper/zaproxy,0xkasun/zaproxy,mario-areias/zaproxy,0xkasun/zaproxy,Ali-Razmjoo/zaproxy,Ye-Yong-Chi/zaproxy,Harinus/zaproxy,veggiespam/zaproxy,robocoder/zaproxy,gmaran23/zaproxy,rajiv65/zaproxy,jorik041/zaproxy,NVolcz/zaproxy,tjackiw/zaproxy,meitar/zaproxy,gmaran23/zaproxy,0xkasun/zaproxy,UjuE/zaproxy,psiinon/zaproxy,kingthorin/zaproxy,surikato/zaproxy,pdehaan/zaproxy,mario-areias/zaproxy,mario-areias/zaproxy,thc202/zaproxy,urgupluoglu/zaproxy,NVolcz/zaproxy,profjrr/zaproxy,psiinon/zaproxy,UjuE/zaproxy,ozzyjohnson/zaproxy,MD14/zaproxy,meitar/zaproxy,Ye-Yong-Chi/zaproxy,Ali-Razmjoo/zaproxy,rajiv65/zaproxy,Harinus/zaproxy,NVolcz/zaproxy,psiinon/zaproxy,DJMIN/zaproxy,surikato/zaproxy,UjuE/zaproxy,urgupluoglu/zaproxy,zapbot/zaproxy,gsavastano/zaproxy,robocoder/zaproxy,DJMIN/zaproxy,Ye-Yong-Chi/zaproxy,thamizarasu/zaproxy,mustafa421/zaproxy,gsavastano/zaproxy,JordanGS/zaproxy,JordanGS/zaproxy,robocoder/zaproxy,efdutra/zaproxy,Harinus/zaproxy,Ye-Yong-Chi/zaproxy,Harinus/zaproxy,profjrr/zaproxy,0xkasun/zaproxy,cassiodeveloper/zaproxy,thc202/zaproxy,Ali-Razmjoo/zaproxy,Ye-Yong-Chi/zaproxy,pdehaan/zaproxy,tjackiw/zaproxy,thamizarasu/zaproxy,zapbot/zaproxy,gsavastano/zaproxy,thamizarasu/zaproxy,DJMIN/zaproxy,NVolcz/zaproxy,mabdi/zaproxy,lightsey/zaproxy,surikato/zaproxy,gsavastano/zaproxy,rajiv65/zaproxy,Ali-Razmjoo/zaproxy,kingthorin/zaproxy,0xkasun/zaproxy,MD14/zaproxy,psiinon/zaproxy,jorik041/zaproxy,surikato/zaproxy,cassiodeveloper/zaproxy,profjrr/zaproxy,Harinus/zaproxy,DJMIN/zaproxy,JordanGS/zaproxy,zaproxy/zaproxy,tjackiw/zaproxy,meitar/zaproxy,thc202/zaproxy,JordanGS/zaproxy,mustafa421/zaproxy,lightsey/zaproxy,zaproxy/zaproxy,rajiv65/zaproxy,zapbot/zaproxy,urgupluoglu/zaproxy,meitar/zaproxy,meitar/zaproxy,0xkasun/zaproxy,jorik041/zaproxy,robocoder/zaproxy,gmaran23/zaproxy,urgupluoglu/zaproxy,Harinus/zaproxy,mario-areias/zaproxy,JordanGS/zaproxy,kingthorin/zaproxy,efdutra/zaproxy,zapbot/zaproxy,psiinon/zaproxy,veggiespam/zaproxy,UjuE/zaproxy,tjackiw/zaproxy,cassiodeveloper/zaproxy,zaproxy/zaproxy,Ali-Razmjoo/zaproxy,UjuE/zaproxy,zaproxy/zaproxy,mario-areias/zaproxy,mario-areias/zaproxy,surikato/zaproxy,mabdi/zaproxy,gmaran23/zaproxy,Harinus/zaproxy,zaproxy/zaproxy,NVolcz/zaproxy,ozzyjohnson/zaproxy,mustafa421/zaproxy,mabdi/zaproxy,MD14/zaproxy,mabdi/zaproxy,mustafa421/zaproxy,zapbot/zaproxy,meitar/zaproxy,gsavastano/zaproxy,pdehaan/zaproxy,psiinon/zaproxy,lightsey/zaproxy,jorik041/zaproxy,cassiodeveloper/zaproxy,efdutra/zaproxy,gsavastano/zaproxy,MD14/zaproxy,jorik041/zaproxy,pdehaan/zaproxy,MD14/zaproxy,rajiv65/zaproxy,efdutra/zaproxy,DJMIN/zaproxy,rajiv65/zaproxy,tjackiw/zaproxy,urgupluoglu/zaproxy,rajiv65/zaproxy,profjrr/zaproxy,efdutra/zaproxy,robocoder/zaproxy,ozzyjohnson/zaproxy,gmaran23/zaproxy,psiinon/zaproxy,meitar/zaproxy,veggiespam/zaproxy,profjrr/zaproxy,veggiespam/zaproxy,cassiodeveloper/zaproxy,mabdi/zaproxy,0xkasun/zaproxy,thc202/zaproxy,JordanGS/zaproxy,pdehaan/zaproxy,mustafa421/zaproxy,veggiespam/zaproxy,DJMIN/zaproxy,mabdi/zaproxy,robocoder/zaproxy,kingthorin/zaproxy,zapbot/zaproxy,zaproxy/zaproxy,efdutra/zaproxy,profjrr/zaproxy,urgupluoglu/zaproxy,thc202/zaproxy,ozzyjohnson/zaproxy,Ye-Yong-Chi/zaproxy,DJMIN/zaproxy,zapbot/zaproxy,UjuE/zaproxy,veggiespam/zaproxy,Ali-Razmjoo/zaproxy,JordanGS/zaproxy,surikato/zaproxy,NVolcz/zaproxy,lightsey/zaproxy,mabdi/zaproxy,gmaran23/zaproxy