stb_textedit: end-of-line handling places cursor before newline
stb_truetype: avoid compiler warning due to local vars hiding local vars
readme: add list of one-file libs

fix divide by 0 for exactly-vertical edges;
fix possible divide by 0 for exactly-horizontal edges
add documentation for stbtt_Rasterize;

fix incorrect initialization of alpha channel for RGB PSD

- conversion from int to stbi_uc
- unused parameter

stb_wingraph.h: missing lib pragmas for completeness

Conflicts:
	stb.h

Conflicts:
	stb.h

fix bug where we couldn't rewind a file that reached EOF, which can happen with < 92-byte PIC,PNM,HDR,TGA