Log Message:
libsass: updated to 3.5.4

3.5.4:
Revert sass2scss@v1.1.2 update

3.5.3:
Community
Add nim-sass to implementations list
Add Haskell bindings to implementations list
Add SharpScss and LibSassHost bindings to implementations list
Update node-sass link in implementations list
Update Unicode doc after forcing UTF8/plain ASCII
Update compatibility section of the read me

Features
Update sass2scss@v1.1.2
Emit transparent colours as rgba(0, 0, 0, 0)
Add a sass_option_push_import_extension C-API

Fixes
Fix output/error for modulo zero operation
Fix automake build if sassc is missing
Fix handling of colours in @at directives
Fix edge case converting achromatic colors to HSL
Fix evaluation of arithmetic inside interpolation
Fix handling of @important in custom properties
Fix duplicate definition of out_of_memory macro
Fix merging of nested media queries with negation
Fix regression in parsing selector with trailing escaped colon
Fix segfault on empty custom properties

3.5.2:
Features
Implement more detailed backtraces

Fixes
Fix parsing of block comments to ignore css string rules
Fix win UNC path handling for dot and dotdot directories

3.5.1:
Community
Add sass.cr to implementations list

Fixes
Fix compiler warnings
Fix double free when run in concurrent processes
Fix units sometimes being dropped in math operations
Fix missing error for mixins defined within mixins