initializer-list constructor should not be declared explicit.
Constructors that take a single std::initializer_list
parameter should also omit explicit, in order to support
copy-initialization.

Including
 - usage of static_cast instead of c-style cast,
 - single variable declaration per line,
 - removing const from return types
 - omit unnecessary string to char* conversions,

The used clang-tidy checks are:
google-readability-casting,
readability-const-return-type,
readability-container-size-empty,
readability-delete-null-pointer,
readability-deleted-default,
readability-else-after-return,
readability-function-size,
readability-identifier-naming,
readability-inconsistent-declaration-parameter-name,
readability-isolate-declaration,
readability-misleading-indentation,
readability-misplaced-array-index,
readability-named-parameter,
readability-redundant-*,
readability-simplify-*,
readability-static-accessed-through-instance,
readability-static-definition-in-anonymous-namespace,
readability-string-compare,
readability-uniqueptr-delete-release

Most of the current .clang-tidy contained checks:
google-explicit-constructor
google-readability-braces-around-statements
modernize-loop-convert
modernize-use-default-member-init
modernize-use-emplace
modernize-use-using
readability-braces-around-statements
readability-else-after-return
readability-named-parameter
*readability-namespace-comments
*readability-inconsistent-*
readability-redundant-member-init
readability-simplify-boolean-expr
readability-string-compare
*explicit-conversions*

Move netcdf dialog directory include keeping NetCDF cmake code together.

Clang format run on near-the-header lines.

Happy New Year

See clang-tidy docu https://clang.llvm.org/extra/clang-tidy/checks/readability-simplify-boolean-expr.html

This potentially saves a second copy compared to using const
reference. See Effective Modern C++, Item 41.

Especially on iterator types and 'new' allocations.

Disabled PCH on Visual Studio 2015.

When building shared libraries -DBUILD_SHARED_LIBS=On must be passed to the
cmake invokation. Otherwise the default static linking applies.

This reduces the compile time, which is especially interesting for the debug
builds.