Add first pass of some prepared statement functions

This code doesn't work yet
Add first pass of some prepared statement functions

This code doesn't work yet
Merge branch 'prepared_statement' of github.com:LinuxJedi/libattachsql into prepared_statement
Fixed potential buffer pointer breakage
Merge pull request #70 from LinuxJedi/buffer_pointers

Fixed potential buffer pointer breakage
Docs fixups
Add Travis test without SSL and zlib

Fixes #71
Prepare sending works

Not much else in this tree works yet
Execute works

Can't read data yet, but getting there
Param set functions now work
Statement row processor
Prepared statement get functions
Final linkup of prepared statement functions
Add prepared statement docs
Add first pass of some prepared statement functions

This code doesn't work yet
Prepare sending works

Not much else in this tree works yet
Execute works

Can't read data yet, but getting there
Param set functions now work
Statement row processor
Prepared statement get functions