Because "keymiss" is "special" compared to the rest of
the notifications (Trying not to break existing apps
using the 'A' format for notifications)

Also updated redis.conf and module.c docs

currently there's no bug since the flags these functions handle are
always lower than 32bit, but still better fix the type to prevent future
bugs.

using panic rather than exit means you get s stack trace of the code
path that experianced the error, and possibly other info.

This bug affected RM_StringToLongDouble and HINCRBYFLOAT.
I added tests for both cases.

Main changes:
1. Fixed string2ld to fail if string contains \0 in the middle
2. Use string2ld in getLongDoubleFromObject - No point of
   having duplicated code here

The two changes above broke RM_SaveLongDouble/RM_LoadLongDouble
because the long double string was saved with length+1 (An innocent
mistake, but it's actually a bug - The length passed to
RM_SaveLongDouble should not include the last \0).

If a blocked module client times-out (or disconnects, unblocked
by CLIENT command, etc.) we need to call moduleUnblockClient
in order to free memory allocated by the module sub-system
and blocked-client private data

Other changes:
Made blockedonkeys.tcl tests a bit more aggressive in order
to smoke-out potential memory leaks

With the previous API, a NULL return value was ambiguous and could
represent either an old value of NULL or an error condition. The new API
returns a status code and allows the old value to be returned
by-reference.

This commit also includes test coverage based on
tests/modules/datatype.c which did not exist at the time of the original
commit.

This is useful to tell redis and modules to try to avoid doing things that may
increment the replication offset, and should be used when draining a master
and waiting for replicas to be in perfect sync before a failover.

in case of nested MULTI/EXEC

Random command like SPOP with count is replicated as
some SREM operations, and store them in also_propagate
array to propagate after the call, but this would break
atomicity.

To keep the command's atomicity, wrap also_propagate
array with MULTI/EXEC.

RM_Call() will now use EBADF and ENONET in addition to EINVAL in order
to provide more information about errors (i.e. when return value is
NULL).

trimming talk about RESP protocol from API docs (should be independent to that anyway)

This is a light-weight replace function, useful for use cases such as
realloc()ing an existing value, etc.  Using RM_ModuleTypeSetValue() in
such cases is wasteful and complex as it attempts to delete the old
value, call its destructor, etc.

- Adding RM_ScanKey
- Adding tests for RM_ScanKey
- Refactoring RM_Scan API

Changes in RM_Scan
- cleanup in docs and coding convention
- Moving out of experimantal Api
- Adding ctx to scan callback
- Dont use cursor of -1 as an indication of done (can be a valid cursor)
- Set errno when returning 0 for various reasons
- Rename Cursor to ScanCursor
- Test filters key that are not strings, and opens a key if NULL

The implementation expose the following new functions:
1. RedisModule_CursorCreate - allow to create a new cursor object for
keys scanning
2. RedisModule_CursorRestart - restart an existing cursor to restart the
scan
3. RedisModule_CursorDestroy - destroy an existing cursor
4. RedisModule_Scan - scan keys

The RedisModule_Scan function gets a cursor object, a callback and void*
(used as user private data).
The callback will be called for each key in the database proving the key
name and the value as RedisModuleKey.