Add custom font

[Info 3bits]

Add an option to use a custom font:

• Add "Custom" as an option to the Fonts selector
• Add a field to enter the font name
• Files must be located in /font folder

[Info 3bits]

fix #948 Add custom font option

→ <<cset 25bd8c7696d4>>

[Info 3bits]

fix #948 correct some bugs and add header and title

→ <<cset 0a6bb9f8fad2>>

[Info 3bits]

fix #948 correct some bugs and add header and title

→ <<cset 0ad34f371b18>>

[Info 3bits]

fix #948 correct some bugs and add header and title

→ <<cset 09e27222c68f>>

[Info 3bits]

fix #948 correct some bugs and add header and title custom font

→ <<cset 85aac4e07c0c>>

[Info 3bits]

Rolled back the changes until get a better approach to add a custom font

[Info 3bits]

fix #966 #948 revert custom font changes

→ <<cset ce7f447a9b73>>

[Info 3bits]

The existing approach add junk code.

Try to find out a better approach.