Manual merge with wilmer's approach to handling missing protocols

Turns out he already implemented pretty much the same thing in the
parson branch... last year.

The differences between the two approaches are subtle (there aren't too
many ways to do this, some lines are the exact same thing) but I decided
I like his version better, so this mostly reverts a handful of my
changes while keeping others. The main advantage of his approach is that
no fake protocols are registered, no actual prpl functions are called,
and the missing prpl is a singleton constant.

New things compared to the implementation in the other branch:

- The explain_unknown_protocol() function.
- Fixed named chatrooms throwing a warning and losing the "account"
  setting when saving. See changes in irc_im.c
- Fixed the "server" setting dropping when saving. See account.c

Differences with my previous implementation:

- Accounts with missing protocols don't autoconnect
- 'account list' marks them as "(missing!)"

1 files changed, 0 insertions, 4 deletions

diff --git a/protocols/nogaim.h b/protocols/nogaim.h
index 3aa89c3b..8e6c9d5a 100644
--- a/protocols/nogaim.h
+++ b/protocols/nogaim.h
@@ -158,9 +158,6 @@ typedef enum {
 
 	/* The protocol is not suitable for OTR, see OPT_NOOTR */
 	PRPL_OPT_NOOTR = 1 << 12,
-
-	/* This prpl is a placeholder for a missing protocol */
-	PRPL_OPT_UNKNOWN_PROTOCOL = 1 << 13,
 } prpl_options_t;
 
 struct prpl {
@@ -323,7 +320,6 @@ G_MODULE_EXPORT GList *get_protocols_disabled();
 G_MODULE_EXPORT GSList *get_connections();
 G_MODULE_EXPORT struct prpl *find_protocol(const char *name);
 G_MODULE_EXPORT gboolean is_protocol_disabled(const char *name);
-G_MODULE_EXPORT struct prpl *make_unknown_protocol(const char *name);
 G_MODULE_EXPORT char *explain_unknown_protocol(const char *name);
 /* When registering a new protocol, you should allocate space for a new prpl
  * struct, initialize it (set the function pointers to point to your