Several consumer-oriented fixes

See merge request !27

This allows it to be used in the GObject introspection

Fixes some missing symbols that are supported by Vala but not by the
GObject introspection yet.

The pkg-config is only declaring the rest-1.0 directory so we always need to use
rest/rest-foo.h and not rest-foo.h

Also make sure to include all the headers.

The parameters are not optional as they are always accessed. They can be NULL
when the iter is finished, actually always set it so that we are sure to
always have an initialized variable

Allows bindings to use the single header

Release 0.9.1

See merge request !26

OAuth1 is discouraged to be used nowadays. Only flickr is the only
service we used in the past which needed oauth1. They probably
won't update their API to OAuth2 and therefore it was dropped
in GOA. Following this example, dropping OAuth1 support too for librest.

meson: Add soupapiversion to pkg-config file

Closes #12

See merge request !25

Fixes #12

meson: build with soup3 by default

Closes #11

See merge request !24

Fixes #11

Allow convenient use of librest as a subproject

See merge request !23

Meson allows projects to specify the dependency object when used as
subprojects; this avoids having to know the variable name to import into
the superproject.

See: https://mesonbuild.com/Reference-manual_builtin_meson.html#mesonoverride_dependency

This fixes problems with bindings if they want to free resources

ci: Use upstream check-abi

See merge request !21

OAuth2Proxy.fetch_access_token: Provide client secret

See merge request !20

build: Fix typo

See merge request !19

demo: add status to oauth buttons

See merge request !18

ci: fix path to check-api script

See merge request !17

Some build fixes

See merge request !16

This tests the libsoup2 build of the examples.

librest/examples/demo/demo-rest-page.c: In function ‘on_send_clicked’:
librest/examples/demo/demo-rest-page.c:498:24: error: too few arguments to function ‘soup_logger_new’
  498 |   SoupLogger *logger = soup_logger_new (SOUP_LOGGER_LOG_BODY);
      |                        ^~~~~~~~~~~~~~~
In file included from /usr/include/libsoup-2.4/libsoup/soup.h:31,
                 from librest/examples/demo/demo-rest-page.c:23:
/usr/include/libsoup-2.4/libsoup/soup-logger.h:59:13: note: declared here
   59 | SoupLogger *soup_logger_new         (SoupLoggerLogLevel  level,
      |             ^~~~~~~~~~~~~~~

../rest/rest-params.c:224: Warning: Rest: rest_params_as_string_hash_table: unknown parameter 'self' in documentation comment, should be 'params'

../rest/rest-oauth2-proxy.c: In function ‘rest_oauth2_proxy_build_authorization_url’:
/usr/include/glib-2.0/glib/glib-autocleanups.h:28:3: warning: ‘params_string’ may be used uninitialized [-Wmaybe-uninitialized]
   28 |   g_free (*pp);
      |   ^~~~~~~~~~~~
../rest/rest-oauth2-proxy.c:355:21: note: ‘params_string’ was declared here
  355 |   g_autofree gchar *params_string;
      |                     ^~~~~~~~~~~~~

../rest/rest-oauth2-proxy.c: In function ‘rest_oauth2_proxy_new_call’:
/usr/include/glib-2.0/glib/glib-autocleanups.h:28:3: warning: ‘auth’ may be used uninitialized in this function [-Wmaybe-uninitialized]
   28 |   g_free (*pp);
      |   ^~~~~~~~~~~~
../rest/rest-oauth2-proxy.c:114:21: note: ‘auth’ was declared here
  114 |   g_autofree gchar *auth;
      |                     ^~~~

Flatpak demo build

See merge request !15