implement character validation methods in XmlConvert. Fix bug #11910.
[sdb] Improve logging a bit.
[llvm] Avoid adding methods which failed llvm compilation to 'mono.function_indexes'.
[llvm] Disable LLVM for async methods to work around #13734.
[System.Core/Android] Support Android v4.3's timezone DB format

Fixes: https://bugzilla.xamarin.com/show_bug.cgi?id=13686

Android v4.3 changed the timezone DB format described in 8a263984 and
replaced it with a single file containing version, index, data, and a
"zoneTab" (which is parsed but unused).

Port/rewrite the Java libcore.util.ZoneInfoDB type into
System.AndroidTzData so that this new file format is supported.

(Another day, another file format...)
Fix a mixed-decls-and-code warning.
Fix a warning in dlmalloc by #if 0'ing an unused function.
Fix some warnings in strtod by #if 0'ing some unused functions.
Create correct flow branching for single non-default switch section. Fixes #13736
Kill another mixed-decls-and-code warning.
Add two unnecessary zero initializations to shut GCC up.

The conditions are too complex for GCC to realize that these variables
are actually initialized when they're used.
Fix another strtod warning with #if 0.
Fix an unlikely case in cmd_to_string () where cmds would be accessed uninitialized.
Add support for exclude files in extension modules.
[build]Bring some sanity to the monotouch profiles.

monotouch is now the static profile and it does define FULL_AOT_RUNTIME globally.