Combine V_IMMUTABLE and FILENAME changes on PidFile.

Regenerate the exceptions file, but only commit the improvements.

Includes changes from 32213 and other tickets.

Part of 32213.

Fixes bug 32371; bugfix on 0.4.0.1-alpha.

Fixes bug 32370; bugfix on 0.4.1.2-alpha.

Part of 32213.

Part of 32213.

This is an automated commit, generated by this command:

./scripts/maint/rename_c_identifier.py \
        get_dirportfrontpage relay_get_dirportfrontpage \
        parse_port_config port_parse_config \
        count_real_listeners port_count_real_listeners \
        parse_transport_line pt_parse_transport_line \
        ensure_bandwidth_cap config_ensure_bandwidth_cap \
        get_effective_bwrate relay_get_effective_bwrate \
        get_effective_bwburst relay_get_effective_bwburst \
        warn_nonlocal_ext_orports port_warn_nonlocal_ext_orports \
        parse_ports_relay port_parse_ports_relay \
        update_port_set_relay port_update_port_set_relay \
        get_transport_bindaddr_from_config pt_get_bindaddr_from_config \
        get_options_for_server_transport pt_get_options_for_server_transport

It was generated with --no-verify, because it has some long lines.

Part of 32213.

Tests relay/relay_config.c.

Part of 32213.

Tests relay/transport_config.c.

Part of 32213.

Obviously correct fixes on already reviewed code.

Obviously correct fixes on already reviewed code.

Obviously correct fixes on already reviewed code.

Obviously correct fixes on already reviewed code.

Obviously correct fixes on already reviewed code.

This change makes sure we are always using the coverage binary, when
coverage is enabled.

Fixes bug 32368; bugfix on 0.2.7.3-rc.

Fixes bug 32352; bugfix on 0.0.9pre6.

Part of 32213.

Part of 32213.

Part of 32213.

(This copies documentation from doc/HACKING/design, and edits for
concisensess and clarity.)

This one was missed by the perl script in the last commit because
it spanned a newline.

This commit was generated with:

find src -name '*.dox' |xargs perl -i -pe 's{\\ref src/(\S+) \"\S+}{\\refdir{$1}};'

We need to use this kind of trickery to make directory links work in
out-of-tree builds.

This commit was automatically generated with:

find src -name '*.dox' |xargs perl -i -pe 's{\@dir ([^/])}{\@dir /$1};'

This commit takes descriptions for src/lib and moves them into our
doxygen hierarchy.  I've covered everything from lib/cc through
lib/sandbox here.