This commit adds support for aliasing component names. A component
name alias is created by calling: mca_base_alias_register. The name
of the project and framework are optional. The component name and
component alias are required. Once an alias is registered all
variables registered after the alias creation will have synonyms
also registered. For example:
```c
mca_base_alias_register("opal", "btl", "vader", "sm", false);
```
would cause all of the variables registered by btl/vader to have
aliases that start with btl_sm. Ex: btl_vader_single_copy_mechanism
would have the synonym: btl_sm_single_copy_mechanism.
If aliases are registered before component filtering the alias
can also be used for component selection. For example, if sm is
registered as an alias to vader in the btl framework register
function then ```--mca btl self,sm``` would be equivalent to
```--mca btl self,vader```.
Signed-off-by: Nathan Hjelm <hjelmn@google.com>
9fae5bfdf3