remove unecessary inclusion of desktop search header in content
header which has knock on effect of not having ctype or string
system headers dragged in unecessarily.
Futher this highlighted use of ctype API where internal ascii
processing ought to be used.
This reduces the source complexity of the html_mouse_action()
previously this was a single function of several thousand
lines with over 30 local variables allocated on the stack.
Variables are now mostly held in a single static structure which
drasticaly reduces the size of stack frame required and improves
lookup locality.
The generated code does cause two additional function calls as the
compiler avoids inlining the sub functions. The optimiser seems to
produce somewhat better code within the sub functions.
In the final analysis there appears to be no significant performance
loss or gain with this change, just more readable source.
This redundant code was added by:
4747bbbfb2 HTML drags now go via content msg.
and then added again with:
c2a718075a A load of refactoring of how content selection and input work.
