LoadLibrary hooking improvements.

Don't hook ourself from LoadLibrary or LoadLibraryEx.
Test additional LoadLibraryEx flags before deciding to hook.
Always find the base address of kernel32.dll.
Inject by adding to the Import Directory Table.

-p uses CreateRemoteThread, determining kernel32.dll & LLW dynamically.
Loading via LoadLibrary will remember the current attributes, restoring them on
unload.
Tweaked log output (remove quotes around CreateProcess command line; add an
underscore to 64-bit addresses).
ansicon.exe will really output (to the console) strings as Unicode.
Fixed ansicon.exe, if installed, restoring the default attributes, not current.
ansicon.exe will start with ANSICON_DEF (if defined and -m not used).
Work with 64-bit AnyCPU; copy original IDT to IAT; log improvements.
Fixed restoring original attributes on detach.
Attributes and saved position are local to each console window.
Exclude entire programs; better hooking of dynamically-loaded libraries.

ANSICON_EXC can now be used to exclude an entire program (including children).
This is achieved by simply not specifying an extension: ANSICON_EXC=program.exe
will just ignore program.exe (its DLLs will still be hooked, as will its child-
ren), but ANSICON_EXC=program will not hook program at all (which also means
its children will not be hooked).

The various LoadLibrary hooks would only hook the DLL that was specified - any
DLLs it loaded would be missed.  That has now been rectified.  Similarly, a DLL
that is injected via CreateRemoteThread, using LoadLibraryA or LoadLibraryW as
its ThreadProc, will now be hooked.
Better parsing of escape & CSI sequences.

Recognise general Parameter & Intermediate Bytes, rather than testing
specific characters.  Explicitly ignore xterm 38 & 48 SGR values.
Use window height, not buffer.

Clear screen (\e[2J) will scroll in a new window the first time it's used,
or the window has scrolled, or the cursor is on the last line of the buffer.

Restore Cursor Position (\e[u) will recognise screen size changes and limit
itself to the new boundaries.
Recognise more sequences; ignore newline immediately after wrap.

Added support for CHT & CBT (move forward/backward by tabs), DECAWM (don't
wrap at EOL), CRM (display control characters, but still perform newline)
and REP (repeat last character, including BEL, BS, TAB, LF and CR).

It always bugged me that newline would add an unneeded blank line due to
wrap, but not enough to do anything about it.  For some reason, adding CRM
got me to thinking about it, so I finally did it.

Stopped \e[K from erasing the first character of the next line.
Restore cursor visibility on unload.
Converted readme.txt into Markdown.
Merge branch 'readme' of https://github.com/sun/ansicon into sun-readme

Add readme.md, but still keep readme.txt.
Merge branch 'sun-readme'
Remove version history & my postal address from readme.md.