Remove omnisharp--filter-company-candidate

One of the completions being equal to the prefix is usually normal, and
removing it in the backend means idle completion will always try to
suggest completing to something, even if the current text is valid in
the current context.

If removing completions like this is somehow beneficial, it's probably
better performed in `company-transformers`.
company-omnisharp: use `annotation' instead of `crop'

Make use of text properties, they are handy for carrying extra
information.

`omnisharp--make-company-completion' still looks a bit suboptimal
(ideally, annotations would only be calculated when they're
displayed), but omnisharp doesn't seem to return huge completion lists
anyway.

Support for `crop' will be removed in company-mode 0.8, so this kind
of change is sort of mandatory.
Do some reformatting
Drop the auto-complete dependency

The popup.el dependency remains harder to cut out (for example,
`omnisharp-auto-complete-popup-keymap' references `popup-menu-keymap'
in its initvalue form).
Update the README
Merge branch 'develop'
Update cygwin path replacements instructions

The server originally had a json file with the cygwin paths
commented out. However, this changed into a separate file
that needs to be renamed to the config.json file.
Allow using a custom path to the curl program.

This allows using omnisharp-emacs without changing your PATH environment
variable to contain the directory for the curl executable.
Bump version 1.8 -> 1.9
fontified eldoc - requires csharp-mode

semicolon so fontification won't error on some types

don't show semicolon
Async find usages and find implementations
doc strings
Make json deserialization errors more human-readable
Allow user to check whether the OmniSharpServer instance is alive

"Alive" means it is running and not stuck. It also means the connection
to the server is functional - I.e. The user has the correct host and
port specified.
Fix test helper macro giving wrong results

Omnisharp-host would not change
Fix alive status test always failing
Implement checking whether OmniSharpServer is ready
Re-implement flycheck for syntax errors

Closes #66

Revert "Remove syntax checking feature preview from README"

This reverts commit ff662301950bf13175114843e27efd4599774b4f.
Allow the flycheck error parser to work on code issues and QuickFixes

It used to only work on QuickFixes.
Add flycheck checker for code issues (refactoring suggestions)