ELF Tool Chain Code

Turn on SVN keyword expansion.

Ticket: #348

Add `$Id$` keywords.

Ticket: #348

Changes to error handling [part 2 of 2].

* Change macro `DWARF_SET_ERROR()` to take a `Dwarf_Debug` debug context
in its 1st argument. If a `Dwarf_Debug` debug context is unavailable
at the point an error has to be recorded, we use NULL. Actual error
handling is implemented by function `_dwarf_set_error()`.
* Change a few internal helper functions to take an additional Dwarf_Debug
parameter, for use with `DWARF_SET_ERROR()`.
* Replace the redundant use of `DWARF_SET_ERROR()` in `_dwarf_die_add()`
with `assert()`s; parameters `cu` and `abbrev` cannot be NULL if control
has reached this function. While we are here make the function "static".
* Use `DWARF_SET_ERROR()` consistently after a failed called to
`_dwarf_attr_find()`.

Reviewed and revised by: kaiwang27

* Implement consumer de-initialization functions for each DWARF info type.
* Implement producer de-initialization functions for each DWARF info type.
* Call all the consumder de-initialization functions in _dwarf_consumer_deinit().
* Add _dwarf_producer_deinit().

Renamed DWARF_E_INVALID_EXPR to DW_DLE_EXPR_LENGTH_BAD.

Ticket: #20

Renamed DWARF_E_MEMORY to DW_DLE_MEMORY.

Ticket: #20

* Renamed DWARF_E_ARGUMENT to DW_DLE_ARGUMENT.
* Renamed DWARF_E_DEBUG_INFO to DW_DLE_DEBUG_INFO_NULL.

Substitute DWARF_E_NONE with DW_DLE_NONE.

Ticket: #20

Remove redundant inclusions of system headers.

This change allows `libdwarf` to build on FreeBSD 6.

Reviewed by: kaiwang27

Reverted previous commit.

On a second thought: instead of storing the Dwarf_P_Expr pointer and
convert it into block data later during bytes transform, it's much
simpler if we just convert Dwarf_P_Expr to block in the API and save
the block size and data in the attribute.