JIRA: BOTTLENECK-137
Bottlenecks document framwork meeting Danube document requirement.
Changes:
1. Add POSCA testsuite document
2. Combine configuration and installation directory
2.1 https://wiki.opnfv.org/display/DEV/Documentation+Toolchain
3. Change file names in /user_guide
4. Add requirements notes to release notes
5. Add stress test configuartion details
Change-Id: I8d9055097ddae280d985120d4501819d20ad1dcb
Signed-off-by: yuyang <Gabriel.yuyang@huawei.com>