Rewrite of piqic-ocaml on top of "piqi compile" (work in progress)
More work on piqic-ocaml (work in progress)
More work on piqic-ocaml: finally, it generates piqi_piqi.ml for itself
piqic-ocaml can now generate code for piqilib (compiler-complier mode)
New build and bootstrap procedures that don't rely on old piqicc and piqic

The build is a lot simpler and faster now
piqic-ocaml: add generation of multi-format serializers
piqic-ocaml: fix generation of incorrect code for custom ocaml types
Update ocaml examples and tests to use piqic-ocaml instead of "piqic ocaml"
Remove piqic and piqicc and their references

- piqic was superseded by piqic-ocaml
- piqicc was superseded by the new bootstrap procedure
piqic-ocaml: edit comments
Move common piqi compile functionality to piqilib

It is used by piqic-ocaml and "piqi compile"
piqic-ocaml: add deprecation warning for the --gen-defaults flag
piqic-ocaml: fix compilation warning (duplicate piqi_piqi.cmi interface)
piqic-ocaml: add a new --ext flag (same meaning as --multi-format)
doc: update docs to reflect the change from "piqic ocaml" to piqic-ocaml
Update INSTALL.ocaml
piqic-ocaml: various code improvements
Avoid potential build problems by moving piqi_c.idl out of sight

It is not needed for the build, however its presence with a wrong timestamp can
break the build.
piqi compile: remove --normalize-names flag

The original assumption was that by having this implemented in "piqi compile",
piqi compiler backends won't need to implement this logic. It turned out not to
be true, because altering names of the original spec affects multi-format
serialization. We don't want that. So, there's no other choice but have this
logic implemented in all piqi compiler backends directly.
"make install" now installs the piqi.1 manpage

The manpage is now included in the source distribution so that we don't have to
generate it during the build (which would require pandoc).