About the new camel_pstring_add implementation

These can be replaced with the new camel_pstring_add using FALSE as
parameter. Replacing them will also remove the need for the normal
camel_pstring_strdup and therefore also remove the need for the gboolean
own parameter of camel_pstring_add.

camel-folder-summary.c: to->subject = camel_pstring_strdup(from->subject);
camel-folder-summary.c: to->from = camel_pstring_strdup(from->from);
camel-folder-summary.c: to->to = camel_pstring_strdup(from->to);
camel-folder-summary.c: to->cc = camel_pstring_strdup(from->cc);
camel-folder-summary.c: to->mlist = camel_pstring_strdup(from->mlist);

-- 
Philip Van Hoof, software developer at x-tend 
home: me at pvanhoof dot be 
gnome: pvanhoof at gnome dot org 
work: vanhoof at x-tend dot be 
http://www.pvanhoof.be - http://www.x-tend.be