Separate gopher conversion from main binary

Now we use a (much simplified) gopher2html binary in libexec,
instead of converting gopher directories to HTML in loader/gopher.

This has two advantages:
* Less ugly conversion logic in the loader module; we can just
  convert the file line by line. (The previous converter also had
  some correctness issues, that is fixed now as well.)
* If the user desires, they can replace the gopher converter with
  another binary using the mailcap mechanism.

The disadvantages are:
* For now, source display is broken. This is a problem with all
  mailcap filters in general, and should be fixed in the future. (That
  said, the previous version also only displayed the converted HTML
  source, which was not really useful anyway.)
* The proper directory structure is required for this to work;
  OTOH plenty of work has been done so that this is as frictionless as
  possible, so it should not really be a problem.

1 files changed, 6 insertions, 1 deletions

diff --git a/doc/build.md b/doc/build.md
index d04c290a..bb9f929d 100644
--- a/doc/build.md
+++ b/doc/build.md
@@ -36,11 +36,16 @@ also override them by setting an environment variable with the same name.
 * `MANPREFIX`, `MANPREFIX1`, `MANPREFIX5`: prefixes for the installation of
   man pages. The default setting expands to `/usr/local/share/man/man1`, etc.
 * `CURLLIBNAME`: Change the name of the libcurl shared object file.
+* `LIBEXECDIR`: Path to your libexec directory; by default, it is relative
+  to wherever the binary is placed when it is executed.<BR>
+  WARNING: Unlike other path names, this must be quoted if your path contains
+  spaces!
 
 ## Phony targets
 
+* `all`: build all required executables
 * `clean`: remove OBJDIR, OUTDIR, and the QuickJS library
-* `manpage`: build man pages
+* `manpage`: build man pages; note that this is not part of `all`
 * `install`: install the `cha` binary, and if man pages were generated,
   those as well
 * `uninstall`: remove the `cha` binary and Chawan man pages