[powershell] Various enhancements

- Commands:
    - remove not workable regex
    - change to use *official-approved verbs* instead
    - add 157 builtin aliases
- Comparison operators:
    - add 47 more operators not been covered
- Keywords (statement):
    - add 28 more keywords not been covered
- Types:
    - add 14 new types highlighting
- Comments:
    - fix a buggy case of block comment
- Quoted text:
    - add a here-string case not been covered

powershell.nanorc

@@ -25,8 +25,8 @@ icolor brightcyan "\<(class|enum|function|using|assembly|command|module|namespac
 icolor green "\<(string|char|byte|int|long|bool|decimal|single|double|DateTime|xml|array|hashtable|void)\>"
 
 ## Comments
-color cyan "#.*$"
 color cyan start="<#" end="#>"
+color cyan "(^|[[:space:]])#[^>].*$"
 
 ## Quoted text
 color brightyellow "\"[^\"]*\""