InlinedVector is not exception-safe

[stephan-tolksdorf]

The insert and emplace methods of InlinedVector don't seem to protect at all against the construction of a new element throwing after existing elements have been moved. If this happens, the vector may be left with uninitialized gaps in the middle of a vector, which will lead to undefined behaviour when e.g. the vector's destructor runs.

[JonathanDCohen]

Please see my comments in #33 and #37