A very, *very* poor-man's version of label<->address dump.  Ugh!
The ASCII characters DEL (127) and US (31) are not printable.
Rework label map collection

This uses a pass to interrogate the system for locations, then dumps
those out instead. It handles includes, anonymous labels, and basic
macros, but it does so in a somewhat ugly way. This data can be
readily abbreviated and should also be re-sorted.
Much prettier label map files
Refactor the label mapper to be more like the lister.
Improvements to c64_0.oph startup/teardown code

16 additional bytes from the zero page are now available; the ZP
locations from $02-$8F are now free for your program's use.

Approximately 128 additional bytes in main RAM are now available,
giving you free reign from $0800-$CFFF. Zero Page backup is now
handled underneath the KERNAL's ROM, with the program epilogue
safely handling swapping out the KERNAL for the duration of the
switch. (IRQs are disabled, and NMI handling code is replicated
and modified to not hurt anything.)

Program exit is now handled by keyboard buffer and jumping
through BASIC's warm reset vector. This technique lets programs
play more nicely with PUCRUNCH and onefilers (which otherwise
often confused BASIC as the BASIC prologue would change as part
of decompression or link-loading).
Add libbasic64, for using BASIC's floating point in assembler programs
Merge pull request #22 from catseye/printable-chars-in-listing

Good catch. Merging that in 2.1.
Refactor c64_0.oph to include a minimal BASIC loader
libbasic64 is now vaguely usable

More consistent set of macros for interacting, a string-reader,
and better-documented preconditions based on disassemblies
libbasic64 sample program
Range-check inputs on kinematics example