Fix documentation indentation for constraints

Due to inconsitent use of space and tabs, as well as some typos,
the documentation for implicit constraint does not show up properly.
This has been fixed in this commit.

include/hpp/constraints/explicit.hh

@@ -60,7 +60,8 @@ namespace hpp {
         & \mbox {if and only if}\\
         \mathbf{q}_{out} &= f \left(\mathbf{q}_{in}\right) + rhs \\
         \f}
-	If function \f$f\f$ takes values in a Lie group (SO(2), SO(3)),
+
+        If function \f$f\f$ takes values in a Lie group (SO(2), SO(3)),
         the above "+" between a Lie group element and a tangent vector
         has to be undestood as the integration of the constant velocity from
         the Lie group element:

include/hpp/constraints/implicit.hh

@@ -36,7 +36,7 @@ namespace hpp {
     /**
         This class represents a parameterizable numerical constraint that
         compares the output of a function \f$h\f$ to a right hand side Lie
-	group element.
+        group element.
 
         \par Definition
 
@@ -46,7 +46,7 @@ namespace hpp {
         respectively \f$(n_q,n_v)\f$.
         \li The comparison is represented by a vector \f$\mathbf{c}\f$ of
         dimension \f$n_v\f$ with values in
-        enum hpp::contraints::ComparisonType = {
+        enum hpp::constraints::ComparisonType = {
         \f$\mathbf{Equality}\f$, \f$\mathbf{EqualToZero}\f$,
         \f$\mathbf{Inferior}\f$, \f$\mathbf{Superior}\f$ }.
         \li The right hand side is Lie group element of dimension \f$n_q\f$.
@@ -71,23 +71,24 @@ namespace hpp {
         \f$e_i = \Delta_i\f$,
         \li if \f$c_i\f$ is \f$\mathbf{EqualToZero}\f$, \f$e_i = \Delta_i\f$.
 
-	\par Mask
+        \par Mask
 
-	A mask is a vector of Boolean values of size \f$n_v\f$. Values set to
-	false means that the corresponding component of the error defined above
-	is not taken into account to determine whether the constraint is
-	satisfied. The active rows of the constraint may be accessed via
-	method activeRows.
+        A mask is a vector of Boolean values of size \f$n_v\f$. Values set to
+        false means that the corresponding component of the error defined above
+        is not taken into account to determine whether the constraint is
+        satisfied. The active rows of the constraint may be accessed via
+        method activeRows.
 
         \par Parameterizable right hand side
 
-        Lines with \textbf{Equality} comparator in the above definition of the
-        error need a parameter, while lines with comparators \textbf{Inferior},
-        \textbf{Superior}, or \textbf{EqualToZero} do not.
-        As a consequence, the right hand side of the constraint is defined by
-        a vector \f$\lambda\f$ of parameters of size the number of
-        \textbf{Equality} occurences in vector \f$\mathbf{c}\f$. The right hand
-        side is then defined as in the following example:
+        Lines with \f$\mathbf{Equality}\f$ comparator in the above definition
+        of the error need a parameter, while lines with comparators
+        \f$\mathbf{Inferior}\f$, \f$\mathbf{Superior}\f$, or
+        \f$\mathbf{EqualToZero}\f$ do not. As a consequence, the right hand
+        side of the constraint is defined by a vector \f$\lambda\f$
+        of parameters of size the number of \f$\mathbf{Equality}\f$ occurences
+        in vector \f$\mathbf{c}\f$. The right hand side is then defined as in
+        the following example:
         \f[
         rhs = \exp\left(\begin{array}{c}\lambda_1 \\ 0 \\ 0 \\ \lambda_2 \\
         \vdots \end{array}\right)