Add more stylings for the corners square and dot options

[vnkapoor]

I want to add more style for the corners square and dot options. I want to add the corners styling as per below. Is there any way to customize this?
Below is the reference image which types of styles I wants

[chrisspiegl]

This seems to be getting worked on in (and appears to be a duplicate of):

• New styles to the library ? #46

With pull request:

• Add Inpoint type for corner square and dot #274