remove header files from src lists
Fix dangling elses

Some dangling else statements were hard to visually parse, and some
actually generated different results than the indentation suggested was
intended.
make wm4_bspline compile with clang++

Pickier compiler caught some technically noncompliant c++  in WM4. Fix
it so that there won't be errors when compiling with clang++.
Don't rely on private _TIFFgetMode

Copy over _TIFFgetMode as part of my removal of all but the necessary
parts of the libtiff inclusion. (Missed that last time, and apparently
the linker found a _TIFFgetMode somewhere -- not a good plan to rely
on.)
Fix unsigned expression problems

True fact: the type of ((unsigned int) + (int)) is unsigned int. Not
good for detecting error conditions where the sum is < 0...
Remove non-ASCII text in src
Abstract base classes need virtual destructors

These base classes have derived classes that are in several cases
passed around (and deleted) while cast as the base classes. Ergo the
base class destructor has to be virtual.
Unsigned long not best for storing float constant
copy_file can't return true on linux/mac
fix ns_sql_connection::set_autocommit

It appears this function simply did not work previously. It also
appears that the function tried two different ways to set autocommit
(via query and via API). I fixed the former, but not the latter because
I'm not exactly sure what's going on.
Prefer _WIN32 over WIN32 define

Seems better to just use one; googling suggests that _WIN32 is possibly
preferable, but what do I know?
Prefer __APPLE__ over __MACH__ define