More detailed Eclim configuration instructions

Knowing those two things (that you need to run latest Eclipse Juno) and you need to create a new project from vim would have saved me a lot of time when trying to make it all work.

I think it's worth adding this information to the README.
Merge pull request #321 from pjg/patch-1

More detailed Eclim configuration instructions
Merge pull request #327 from JazzCore/jedi_upstream_fixes

Switch to upstream Jedi API
Use new Jedi API for keyword checking in goto funcs

Fixes #320
Merge pull request #328 from JazzCore/jedi_keyword_check

Use new Jedi API for keyword checking in goto funcs
Refactoring out some pointless sys.path changes
Calling PrepareClangFlags is not needed anymore

ycm_extra_conf.py files used to import clang_helpers and then use the
PrepareClangFlags function; this is now unnecessary since the logic from that
function has been moved to flags.py. The old PrepareClangFlags function is still
there (it just returns the flags it gets) for the sake of backwards
compatibility with old ycm_extra_conf.py files.
Tests for helper functions in flags.py
Running nosetests after install.sh

ycm_core.so needs to be built for the tests to run. The python code imports
ycm_core, so it needs to be present.
Removing jedi submodule
Moving everything under pytho/ycm
Adding back the Jedi submodule
Fixing python tests broken in rename
API docs for ThreadedCompleter
Including `:` in the command names in docs

This will ensure the correct tag is used when we process readme to create the
vimdoc help file. See #330.
Updating vimdoc from README

Fixes #330
Preventing possible TypeError with StringVec

It was possible to get a traceback if results[ 'flags' ] was a StringVec; the
code would try to perform results[ 'flags' ] += self.special_clang_flags and
this would then fail because the clang flags would be a Python list.
Fix breakage of some compile_commands.json users

Depending on the user, the PrepareClangFlags rewrite of a few commits ago could
break users with an extra "clang: 'linker' input not used" (or similar) error
message because the compiler executable string was not removed from flags
upstream if the user prepended some flags to the output of PrepareClangFlags
before returning it to the caller of FlagsForFile.

Since the rewrite was supposed to be backwards compatible, this needs
to be handled.
Adding the ClearCompilationFlagCache subcommand

With this command the user can clean the in-memory cache of the compilation
flags that the clang completer uses.
Small README doc rewording