Adds more unit tests (many more to come)

Finalizes support for the TME api

package updates required for build

appveyor version bump

Fixed mouser api so Test functionality works if only orders api is en…

…abled.

Fixed mouser order import to allow import even if search api key is not enabled (more minimal data is returned)

a fix for filtering part types via the selector control, broken durin…

…g memoization changes.

forced focused css style as well

Fixes an obscure bug that was discovered by @TWM617 - if a configurat…

…ion section is missing (such as newly introduced integrations) it should not be defaulted to true. The new configuration validation feature revealed this problem as it validates enabled integration apis for proper settings on startup.

Fixes #191 - a part was discovered that DigiKey returns multiple moun…

…ting types for ??, so needed to handle the edge case.

Also, another memoization issue found when barcode scanning part quantities losing the correct value due to multiple api lookups. A better fix needs to be followed up with at a later time.

adds a dedicated targetframework for the temp external project to wor…

…k around a solution level msbuild limitation.

fixes #190 - fixed some issues with whitespace treatment