Merge pull request #384 from penggrin12/many-constexpr

Add `constexpr`s wherever possible without a warning

Merge pull request #382 from Another52/master

Add const overload for GetTexture method

v5.5.1

Merge pull request #375 from lucas-watkins/master

Method overloads for `Texture::Load` to unload previous texture before loading new texture

Merge pull request #373 from und3f/add-vec-add-sub-float-operations

Add vector add/sub float operations

Merge pull request #372 from und3f/add-effc++-test-flag

Add test compile warning flag effc++ and fix findings

Merge pull request #371 from und3f/fix-oldstyle-const-cast-warning

Fix use of old-style cast

Merge pull request #369 from mikomikotaishi/patch-1

Update modules examples to use using statements