fix compiler warnings about missing end of file newlines

* added terminal newlines to some specific files which caused compiler warnings
Correctly interpret variable interpolants in @import css statements. Fixes #367
Merge pull request #373 from wonja/interpolants_in_css_imports

Correctly interpret variable interpolants in @import css statements. Fix...
reorder initializer list to correspond to class member definition order

* fixes ''Sass::Context::c_functions' will be initialized after... warning
Merge pull request #375 from rivy/rivy-fix-EOF.newlines

fix compiler warnings about missing end of file newlines
Merge pull request #376 from rivy/fix-context.cpp

reorder initializer list to correspond to class member definition order
updating the submodule
catching up to hcatlin
Keep multiline loud comments in compressed output. Fixes #348
Merge pull request #378 from wonja/loud_comments

Loud comments
Allow selector lists as arguments to pseudo selectors. Fixes #288
Allow trailing commas in lists. Fixes #359
Merge pull request #384 from wonja/wrapped_pseudo_selectors

Allow selector lists as arguments to pseudo selectors. Fixes #288
Merge pull request #385 from wonja/trailing_comma_list

Allow trailing commas in lists. Fixes #359
remove libsass.js upon `make clean`
fixing `make install` (install -D) on OSX

`install -D` does not work on OSX, but since it only creates the target directories, it can easily be split out into a `mkdir -p …`.

```
install -Dpm0755 libsass.a /usr/local/lib/libsass.a
install: illegal option -- D
```
include cstdlib for std::abs() for Emscripten

While gcc compiled fine, emscripten did not. The following error was thrown:

```
/usr/local/bin/emscripten/emscripten/1.8.2/em++ -Wall -O2 -fPIC -c -o utf8_string.o utf8_string.cpp
utf8_string.cpp:111:16: error: call to 'abs' is ambiguous
      else if (std::abs(index) <= signed_len) {
               ^~~~~~~~
```

Either including `cstdlib` or changing `std::abs(index)` to `std::abs((float)index)` fixed the issue with Emscripten without breaking in gcc.
updating the readme and seeing if I can push to the new account
Merge pull request #386 from rodneyrehm/patch-1

remove libsass.js upon `make clean`
Merge pull request #387 from rodneyrehm/patch-2

fixing `make install` (install -D) on OSX