ox-latex: Use options instead of hard-coded variables

ox-latex: Use options instead of hard-coded variables

* lisp/ox-latex.el (org-latex-format-inlinetask-function): Change
  default value.
(org-latex-guess-inputenc, org-latex--text-markup, org-latex-template,
org-latex-clock, org-latex-drawer, org-latex-footnote-reference,
org-latex-headline, org-latex-inline-src-block, org-latex-keyword,
org-latex--inline-image, org-latex-link, org-latex-planning,
org-latex-src-block, org-latex-table, org-latex--org-table,
org-latex--table, org-latex--math-table, org-latex-table-cell,
org-latex-table-row, org-latex-timestamp, org-latex-compile,
org-latex--collect-warnings): Use options instead of hard-coded
variables.

(org-latex-format-inlinetask-default-function): New function.
(org-latex-inlinetask): Use new function.

(org-latex--text-markup): Change signature.
(org-latex-bold, org-latex-code, org-latex-italic,
org-latex-strike-through, org-latex-underline, org-latex-verbatim):
Apply signature change.