Fix compile errors in unit tests on Windows

[chylex]

JVM on Windows doesn't use UTF-8, so compilation of unit test sources with special characters fails on Windows:

assertIsKeyword('Ā');
// unclosed character literal
// unclosed character literal
// not a statement

Discussion: #389

Unfortunately I don't know how to fix the doc folder containing files with quotes, which are illegal on Windows. In case anyone finds this, all I can recommend is this command to remove the doc folder altogether, so that git status doesn't constantly complain about missing files:

git submodule deinit -f doc

[AlexPl292]

Nice!
I wanted to get rid of doc directory as a submodule for some time already, looke like I can do it now.

[chylex]

I think removing the submodule but keeping the .md files will make it worse; removing the submodule effectively hid the illegally named files from git, so it wouldn't cause trouble because it wouldn't even try to pull them into Windows :P

Could you please rename these two .md files

• https://github.com/JetBrains/ideavim/blob/master/doc/%22ideajoin%22-examples.md
• https://github.com/JetBrains/ideavim/blob/master/doc/%22set%22-commands.md

so they don't have quotes in the filename?

[AlexPl292]

Oops, sorry. Actually github wiki forced me to use the quotes in the name, so now it's fine to remove them. Already done.