moving headers to include to mimic modular boost structure
preparing for migration to boost devel
Merging Spirit x3 into devel
fixed wrong include guard
Removing phoenix2 docs and lib stuff
Fix for parsing sequences with x3::unused attribute
Merge pull request #3 from redbaron/parse-into-container-seq-unused-attr

Fix for parsing sequences with x3::unused attribute
Added x3 tests to Jamfile
use std::string as a container for char

That is what normally users would pass, so in some situations it
can avoid copying data.
Added test for recently fixed sequence attribute consistency bug
stop x3::lit from updating passed container
as x3::lit() is fixes no need to omit[] it anymore
make x3::omit[] fail at compile time if it is called with non-unused_type attr

It should never be called with anything but unused_type attribute
anyway, but if something did it due to error it is better to be safe and
fail at compile time rather than unexpectedly  update attribute, which
could lead to hard to detect errors.
unify built container for single element fusion::deque

continue to reduce variety of containers floating inside instantiated
templates.
Make it possible to parse 2 element sequences  directly into fusion map

If parser produces 2 element tuple, then fusion::map can be passed
as an attribute to it. Type of first element in produces tuple is used
as a key and second element is a value stored in map.

Few notes how does it work:
- parsing to fusion::map is treated as parsing to container
- special parse_into_container logic call's parser with it's native
  attribute type (fusion::deque<> for sequences) and then updates
  fusion::map with values from it.
Avoid needless construction of sequence<> parser
Added test for fusion::map parsing
Fix for sequences with only one element producing attr

If in a sequence only one element produces attribute, then make whole
sequence to produce that attribute,rather than wrapping it into
fusion::deque. Not doing so breaks alternative<> parser, when such
sequences are on left and right side of it, because it then generates
variant attribute over fusion:deque<> attributes, which is not
what it is supposed to do. Plus it breaks traits::move_to when both
source and destination are single element fusions sequences. Hence this
fix to put everything back to normal for this edge case.
Support parsing into fusion adapted structs
Merge branch 'fix-one-element-seq' into parse-into-fusion-map