Add parcel prefix to parcel.c and parcel.h

The parcel header file must be publicly available, so add parcel prefix
to avoid name clashes.
Don't include charmony.h in class headers

It's already included via parcel.h.
Add CFISH_VISIBLE alias
Include stdarg.h unconditionally

It's part of C89.
Don't use stdint types in Charmonizer::Probe::Floats

Use a char array to hold the floating point representations of special
values. This is needed for the upcoming changes that add the ability to
create a charmony.h which doesn't define the stdint types.
Split up Charmonizer integer modules

This will allow us to create a charmony.h which doesn't define the
stdint types.
Move stdint typedefs from charmony.h to parcel.h

Change ConfWriterC to move global macro definitions, global typedefs,
and system includes into special sections that can be enabled by
defining macros of the form CHY_EMPLOY_MODULE.

Disable the stdint typedefs in Lucy's charmony.h and move them to
parcel.h.
Regenerate charmonizer.c
Switch from CHY_INLINE to CFISH_INLINE
Switch from CHY_{IM|EX}PORT to CFISH_{IM|EX}PORT
Don't include charmony.h in external code

The public header files don't depend on charmony.h anymore. We still
include charmony.h if CFP_LUCY is defined, but this is only for
convenience. The include could be moved to the C source files now.
Rename hostdefs.h to cfish_hostdefs.h

This header must be publicly available, so add a prefix to avoid name
clashes.
Preliminary installation script

Might be merged into Makefile later.
Allow NULL target in Doc#Extract

Something like a simple Doc#Fetch method might be useful for the C
library.
Sample program using the C library
Fix Charmonizer test

Make sure to employ boolean and integers types.
Fix include file order in lucy_boot.c

lucy_parcel.h must be included early for bool type.
Make install.sh POSIX-compliant
Make charmonizer.c C89-compliant
CFC tests use integer literals from stdint.h