Update bem-pr to 0.10.0

See narqo/bem-pr#87 for details
select: Upside-down arrow becomes cloudy in Fx
Update gemini-screens
Merge pull request #1012 from bem/issues/1010@v2

select: Upside-down arrow becomes cloudy in Fx
popup: split own functionality into target modifiers (close #968)
Merge pull request #1007 from bem/issues/968@v2

popup: split own functionality into target modifiers (close #968)
select: BH-templates refactoring
Merge pull request #1021 from bem/issues/1020@v2

select: BH-templates refactoring
select: Add CSS for examples
Merge pull request #1023 from bem/issues/1022@v2

select: Add CSS for examples
Add to readme section about tmpl-specs
Merge pull request #1024 from bem/issues/1018@v2

Add to readme section about tmpl-specs
select: Tick size does not changed according of the selects's size