Merge pull request #2359 from su2code/release_v8.1.0

Changing version number to 8.1.0

Merge pull request #2223 from su2code/release_v8.0.1

Changing version number to 8.0.1

Merge pull request #2120 from su2code/release_v8.0.0

Changing version number to 8.0.0

Merge pull request #1912 from su2code/release_v7.5.1

Changing version number to 7.5.1

Merge pull request #1848 from su2code/release_v7.5.0

Changing version number to 7.5.0

Merge pull request #1735 from su2code/release_v7.4.0

Changing version number to 7.4.0

Merge pull request #1589 from su2code/release_v7.3.1

Changing version number to 7.3.1

Merge pull request #1518 from su2code/release_v7.3.0

Changing version number to 7.3.0

Merge pull request #1415 from su2code/release_v7.2.1

Changing version number to 7.2.1

Merge pull request #1353 from su2code/release_v7.2.0

Changing version number to 7.2.0