Bug fixes to you

This is a bit unusual beta release; it also brings new features (from pull requests) instead of just fixing bugs. It should be relatively stable, but if you encounter any new bugs, please report them! We're close to a stable release.

• Added an expression to reverse list (thanks @JRoy, closes #2260)
• Added 'summon' as an alias for 'spawn' (thanks @Wealthyturtle)
• Added a condition for checking if strings are alphanumeric (thanks @Wealthyturtle)
• Added support for setting non-living entity names (thanks @Blueyescat, closes #2139)
• Fixed unintended colors in output of Skript's own commands (closes #1269)
• Fixed Skript trying to load non-script files (thanks @Wealthyturtle, closes #2103)
• Fixed documentation of 'ban' effect (thanks @Wealthyturtle, closes #2344)
• Fixed a documentation issue with 'affected entities' expression (thanks @Blueyescat)
• Fixed a broken example in documentation (thanks @Wealthyturtle, closes #1531)
• Fixed Skript preventing boat placement and other interaction issues (closes #2389)
• Fixed removing items ignoring some properties of them (closes #2354)
• Fixed a serious performance issue with 'contains' condition (closes #2393)
• Fixed a memory leak caused by ignoring function return values (closes #2337)
• Fixed functions not being unloaded correctly (closes #2378)
• Fixed default values of function arguments not always being parsed (closes #2353)
• Fixed a regression causing warnings from function parameters (closes #2345)
• Removed prefix from script command 'usage' (thanks @JRoy, closes #1844)
• Improved documentation of 'name' expression (thanks @Blueyescat)