`licenseUrl` is now deprecated, so we use `license expression` instead

Replace TravisCI with AppVeyor for Linux builds

Reduce LogEventLevel boxing

Handwritten implementation of IEnumerator to avoid allocations

Added link to search of Pluralsight courses on readme [skip ci]

Code cleanup

reduces stack alloc

Some very minor cleanup

Update Nuget package license format to new format

use var for out

Wrapped enrichers, conditional/leveled enrichers, conditional sinks

…lts are selected

Use snupkg symbol packages.

Respect explicit format specifiers even when JSON defaults are selected

…tFormatter #1328

…IFormatProvider

made formatProvider optional in the constructor of MessageTemplateTextFormatter

…andard2.0

remove unnecessary System.Collections.NonGeneric dependency for netstandard2.0

…-depth

Update summary for default destructuring depth

fix #1353 Custom format string not accepted by the message
template parser.

Custom numeric format strings may contain plus '+' signs.  That
character was not recognised by the parser.

Allow `+` in message template property format specifiers