This is a clone of #740, but without the amtl ke::AString lowercase which was implemented in a new version of amtl that 1.9-dev isn't pinned to. Updating this pin and moving fixes is beyond what should go in 1.9, and this fixes a annoying and user-impactful bug with reload/unloading plugins on windows.
Currently in 1.9, once a plugin is loaded into the pluginsys, they must be used with lowercase characters *only*, since pr #709 ignorantly modified their names.
```
// test.smx exists in /plugins/
sm plugins load TEST.smx // successful
sm plugins unload TEST.smx // TEST.smx not found, it's actually test.smx
```
This pr fixes that error by converting *all* lookups, not just loads.
* Make mac/win lookups lowercase'd
* Revert #709 & 81042cc
* Adjust HashPolicy implementation across sourcemod
Basically, in order to implement our own (actual) hash policy in
`PluginSys.h`, we needed to remove the blanket implementation of `hash`
that was used before. Now, each policy must implement `hash` along with
`matches` in order to be used with `NameHashSet`. While this does force
us to change every implementation of policies across the entirety of
sourcemod, it allows core to use flexible implementations of `hash`.
* Remove logic duplication
* Improve lowercase checks
When unloading a plugin no plugin is allowed to execute code. There's
been some flawed logic in the scheduling, leading it to bail out if the
plugin was marked for scheduled unloading..
Also change the "error" message of `sm plugins unload` to something
nice.
1. Fixed OnPluginUnloaded not pairing if the plugin failed.
2. Unify error message handling in the second pass.
3. Do not add libraries if a plugin failed during OnPluginStart.
Note: this also ensures that library action callbacks are balanced (i.e., we do not notify
libraries are being dropped if they were never notified as being added).
