remove ThisType from all identifier types

remove `ThisType` (know available with the trait `Resolve<T>`)
use trait `Resolve<T>` instead of ::ThisType

use new trait `Resolve<T>` to get the type out of an alias
Contributions: One-Feature-Per-Pull-Request
Fix Typo, thx @PrometheusPI
Merge pull request #601 from ax3l/doc-oneFeatureAtATime

Contributions: One-Feature-Per-Pull-Request
fix race condition

- fix race condition that field background is removed parallel to the particle pusher
- fix race condition that field update `update_beforeCurrent` run in parallel to the particle pusher
Add Alex Debus, Add PhD's

- Dr./PhD: either one or none
Merge pull request #605 from ax3l/doc-addDevDebus

Add Alex Debus, Add PhD's
Merge pull request #604 from psychocoderHPC/fix-backgroundFieldRacecondition

Fix Race Condition: Field Update and Pusher
Merge pull request #594 from psychocoderHPC/topic-cleanAlias

remove `::ThisType` in all identifier types
Complex-Math: Handle Operations with Scalars

Updated the complex-math library in the radiation-plugin to handle
all basic calculations (+,-,*,/) and assignment from scalars.
Address Review Comments

- own fixes
- @PrometheusPi inlines
- @psychocoderHPC T_Type
Add TWTS Template for BG Field
Draft Redesign TWTS via BG Field

- only for FieldE so far
- not tested for compile